When last we left our heroes, Sarah Jane was blithering for mercy as a Dalek aimed at her, Gwen and Ianto were trying to take out a Dalek with machine guns, and Jack, Donna, and Rose were huddled in the TARDIS watching the Doctor begin regeneration.

As the Doctor turns into a pillar of energy (he must have seen some episodes of Highlander and gotten jealous, because old school regenerations weren't half so sparkly) he suddenly slams his hands together and channels all of the streaming energy into the hand, which is still bubbling away next to the TARDIS console.

"Now then," the still Tennant-shaped Doctor says to his stunned companions.  "Where were we?"  He starts skipping around the console like a weasel on crack - no change there, then - while the three of them stare at him in open mouthed shock.

Because Daleks like to tell you a dozen times what they're going to do before they do it, the pair in front of Sarah Jane are still saying "Exterminate! Exterminate!" when Mickey and Jackie beam in and blow them away with their own versions of Rose's BFG.

"Us Smiths have to stick together," Mickey tells her, but Jackie's not in the mood for any sort of reunion that isn't hers.

"Jackie Tyler, Rose's mum," she tells Sarah Jane. "Now where the hell is my daughter?"

Back at the Torchwood Hub, things have gone all Matrix-y before Gwen has to take a breath from her scream of rage.  The Dalek is frozen and so is the hail of bullets they've sent towards it.  Gwen taps one and gets a rippling effect.

"What the hell?" she asks.

We won't know for a while, however, as we're back in the TARDIS interior, the Doctor on his hands and knees in front of the now-glowing hand.  He blows the sparkles away and technobabbles to the still-stunned Jack, Donna, and Rose about how he siphoned off the extra energy into a "handy biomatching receptacle" because he didn't want to change.  There's a closeup of the hand during this, and I rather wish they hadn't, because that prop is rather the worse for wear these days.  For those who don't remember where the hand came from, the Doctor also goes into a quick recap of The Christmas Invasion.

"You're still you," Rose says launching in for a huge hug.  Donna asks Jack to hug her too, but he uncharacteristically treats it like a huge joke.  It's an OOC moment, considering that it usually takes mace and a chainsaw to keep Jack from flirting and touching.

Back in the Hub, it's Ianto delivering the technobabble; Tosh had finished a time lock program that sealed the Hub into a bubble of time.  This means that Ianto and Gwen are safe, but also that they can't breach the bubble.  "It's all up to Jack now," Ianto says.  Bye, Hub!  It's been nice to see you, but it couldn't be more obvious that your part in the action is over.

The Daleks, very obviously ignorant of the entire previous canon of the show and their own history, have decided to bring the TARDIS onboard their ship.  Using a "temporal prison" that cuts the internal power (much to the Doctor's dismay) the TARDIS is pulled through the atmosphere in some rather decent CGI just as Sarah Jane, Mickey, and Jackie arrive.

Sarah Jane, who had mislaid her inner awesome throughout the entire Stolen Earth episode, has mercifully snapped back to being the kickass leader she portrays in the Sarah Jane adventures.  Announcing that they need to follow, first she asks about the teleports that the others are using.  When Mickey technobabbles that they are dimension jumps as well and need a recharging time, Sarah Jane comes up with plan B on the fly, demanding that they put down their guns. "If they see you with a gun, they'll shoot you dead." Stepping into the street, she surrenders with none of the whining of last week.  As the Daleks announce that she will be taken to the Crucible, Jackie follows on the basis that it's the best chance of finding Rose.  Mickey, outvoted, follows but not before he kisses his BFG goodbye.

Martha has used what she learned last week to program the Indigo backpack.  Announcing to her mother that she must do her duty to UNIT and use the Osterhagen key (the one that Harriet told her must never be used), she jumps... and her only answer when her mother asks what the key does is the cryptic "I love you."

She lands 60 miles out of Nuremberg where, to the great glee of the German fans on my friendslist, the Daleks are shouting "Exterminieren! Halt! Sonst werden wir Sie exterminieren!"  

Back in the TARDIS, it's exposition time.  Jack explains that the Dalek ship Crucible is in the center of the planets.  Rose, whose universe is running ahead of ours, says that "the darkness" has taken over.  She also says that they'd been building a dimension cannon so that Rose could come back to this universe.  The Doctor is quite pleased, despite his warnings back two seasons ago that such things would be catastrophic.  However, Rose does admit that once it started working "dimensions just started to collapse.  Not just in our world.  Something is destroying everything."

At no point does anyone bring up that it is quite likely Rose and the cannon that started this destruction.  The Doctor looks mildly worried, but not half as angry as he had been when Rose tinkered with the fabric of reality in Father's Day or Parting of the Ways.  Donna is concerned about her own future, and Rose explains that the timelines all converge upon her.  "But I'm a temp!" Donna wails for the hundredth time.

Their arrival at the Crucible puts off that explanation. Again.  Instead, the Doctor delivers more exposition, pointing out that these Daleks aren't like the ones they've fought before, that it is a full Empire at the height of its power and understanding.  He doesn't say that they're Daleks modeled on the ones who fought the Time War and forced the Doctor to destroy his own race to defeat them, but he does point out that these are experts at fighting TARDISes, and thus none of the ships shields or defenses will work.

In the background Jack and Rose start debating the use of Rose's dimension jumper (it still needs to recharge "and anyway, I'm not leaving")  and Jack's teleport ("down with the power loss") while in the foreground, Donna is again overwhelmed by the sound of overlapping heartbeats.  The Doctor claims her attention again, apologizing to her and to them all as they go to face the Daleks.  Jack and Rose try to put a good face on it.  The Doctor somberly tells them all, individually, that they were brilliant, and leads the parade outside.

"Daleks reign supreme!  All hail the Daleks!" Nick Briggs shouts in chorus with himself as they file out.  But Donna lags behind, once again distracted by the heartbeat, and the TARDIS slams its door in her face as she goes to leave.

The Doctor yells at the Supreme Dalek to let her out.  The Supreme Dalek returns that this is "Time Lord treachery," that it had nothing to do with the door, and more importantly, the TARDIS was a weapon that will be destroyed.  The TARDIS is dropped down a chute while the Doctor panics and demands its return.

That's far from the Dalek plan.  They have dropped the TARDIS into the core of their own ship, where the radiation will tear it apart, and that Donna is still inside is not a Dalek concern.  "The female and the TARDIS will perish together. Observe," it grates at them.

From the outside, as shown on the Dalek monitor, it looks like the TARDIS is bobbing on molten lava; it's such a Lord of the Rings moment that I'm a little bit surprised that the Doctor never wails "MY PRECIOUS!"  However, David rises above that in a powerful scene begging to die with the TARDIS is Donna's place - "You can do anything to me, just get her out of there!"

Inside, the console room is breaking down; fires roar up through the grating, the console sparks, and rondels are exploding.  (For some reason, that's the scariest part.  We've seen plenty of sparks flying from the console, but the rondels always stay in place.) Donna is screaming and choking until the heartbeat again distracts her.  Only this time, it seems to be coming from the hand in its jar, which she touches.

There is an explosion of energy, around the hand and around her.  

Back on the bridge, the Dalek gloats, "You are connected to the TARDIS.  Now feel it die!"

Donna sits up.  The hand is glowing... and suddenly an entire body glows from around it and sits up as well.

"It's you!" Donna gasps to David Tennant.  "You're naked!"  Alas for the fangirls, you only see him from mid-chest and up.

On the bridge of the Crucible, Rose takes the Doctor's hand.

On the bridge of the TARDIS, the other Doctor punches a button.

On the monitor, the TARDIS flickers and disappears.

Gloatingly, the Supreme Dalek asks the Doctor how he feels, and sneers that if emotions are good, then they have enhanced him with sorrow and despair.  

Jack snaps "Feel this!" and starts shooting with his revolver, getting off only a few shots before he's blasted down. Rose runs to him, obviously unaware of his regenerative powers and her role in them.  

The Doctor pulls her gently away as the Supreme Dalek announces "They are the playthings of Davros now." But just before he lets the Daleks herd him through the door, the Doctor looks back.

Jack winks before closing his eye again.

The battered TARDIS rematerializes among the planets, the other Doctor pulling on a blue suit jacket over a red t-shirt as he babbles about silent running and how important it is to be quiet.  (It is so very characteristic of him that his idea of being silent is to run off at the  mouth.)  

Fandom is a bit divided as to what to call this blue-suited Doctor.  "Handy" is popular, blue suit is indicative, and 10.5 is faster to type.  For plot reasons yet to come, I'm going to stick with "the other Doctor" for now.

Donna is more disgusted than impressed. "Lop a bit off; grow another one?  You're like worms!"

It's a good thing that David can deliver lines at lightening speed, because he's got a lot to go through in this scene; imitating Catherine Tate, being horrified that he's only part Time Lord (the new body has one heart, which human!Doctor announces "Disgusting!"), and delivering lots and lots of exposition.  The high-speed data download includes: explaining himself ("an instantaneous biological metacrisis" because Donna touched the hand full of regeneration energy), the heartbeat ("That was me... you heard me because you were special") and a long psychoanalysis of Donna, whose peppery nature has always been a shield for her insecurity complex. "Shouting at the world because no one's listening.")  Most importantly, he announces that the entire season has been foreordained, but "the pattern's not complete... heading for what?"

Martha's back in Germany, getting chewed out by the little old lady who's the last defender of UNIT's base there, the soldiers having cut and run when the Daleks arrived.  The little old lady talks of the Osterhagen key (alas, no Easter Bunnies) - but those who don't speak German don't know everything she's talking about. 

Until she pulls out the gun.  That's universal.

Martha understands the speech and calmly orders the woman to pull the trigger.  She can't.  The intent, if not the exact wording, is also clear as the woman tells Martha to go to Hell as Martha steps behind a hidden door.

On the Crucible, Jack has been thrown into the incinerator.  Somehow his regeneration powers not only allow him to survive that, but to crawl back out from the wrong side of the hatch without a scorchmark on his coat. Impressive!

Deep in the heart of the castle is a room full of switches and lights, which activates as Martha comes in.  She starts trying to contact the rest of UNIT.

Sarah Jane is upbeat about being told by the Dalek guard that "prisoners will be taken for testing."  As far as she's concerned, they're getting closer to the Doctor every minute.

Rose and the Doctor have been imprisoned in CGI and spotlights, but the Doctor is surprisingly cheerful, because he's figured something out:  Davros is as much a prisoner of the Daleks as he is.  Annoyed, Davros moves on to threaten Rose, but she's equally unimpressed.  It turns out that Caan had foretold Rose's return, "and not even the Supreme Dalek" is willing to mess with one of Caan's predictions.

Caan flipflops and singsongs about one of the companions dying again, and the Doctor starts shouting.  That pleases Davros, who wants the Doctor to reveal his true nature to his companions.  What that precisely is supposed to mean not even Davros knows, but he looks forward to discovering it.

It's time to test the "Reality Bomb" which sounds so much like a 60s spoof movie - probably one starring Peter Sellers - that it's impossible for me to take seriously.  The prisoners are being herded into what looks like a large corridor; when the Daleks are distracted by a woman who falls and panics, Sarah Jane runs to the nearest door, sonics it open with her lipstick, and calls Mickey to freedom. Mickey tries to get Jackie, but she's helping the woman who fell.  Just before the people are literally disintegrated by the harnessed power of all the planets, the dimensional jumpers recharge.  Mickey holds his up before the window in the door, and Jackie teleports out just in time.

Rose and Donna are begging their respective Doctors to explain it, but it's up to Davros to technobabble that the reality bomb cancels out the electrical field holding atoms together, thus blowing whatever it is aimed at into very, very tiny bits.  The Daleks have been using it to blow away the stars that went out, and intend to literally turn all of reality into its component parts, leaving the Daleks as the only life in the galaxy.

The Master would be so jealous if he knew.

On Earth, Sylvia is thrilled to see the Daleks pulling back; she doesn't know that they've been recalled to shield in the Crucible, although Wilf is wary, especially as Donna is still missing.

Jack burst through a ventilation duct to find, by his own description, "Mickey Mouse."  Mickey calls him "Captain Cheesecake" in return before they launch into a happy, slashy hug.  "That's beefcake" Jack tells him. 

"That's enough hugging," Mickey replies.

Jack turns to salute Sarah Jane, who pulls a pendant out of her pocket, one of the many tchotckies she got from the Veren soothsayer.  This one is a Warp Star, which is essentially a portable explosion.  Sarah Jane hands it to Jack.

Martha has her two contacts; it only takes three to use the key.  "Do we do it?" one of her counterpart asks.  "UNIT orders..."

But Martha cites a higher authority.  "There's one more thing the Doctor would do."

On the TARDIS, human!Doctor is working out a way to subvert the gun, by locking it onto Davros.  As all these Daleks except Caan were grown from Davros, it will turn the reality bomb "into the biggest backfire in history."

Martha calls in, and the Supreme Dalek patches the transmission down to Davros and the Doctor, who asks to be allowed to talk to her.  In his corner, Caan burbles and flails, giggling about how "the Children of Time will gather and one of them will die."

"Stop saying that!" the Doctor snaps.  My sentiments exactly.  That's gotten a little old.

Although Martha greets the Doctor, it's Davros who takes the lead, asking her to state her purpose.  The Osterhagen key will detonate 25 nuclear warheads scattered across the planet, blowing Earth to bits.  The Doctor is understandably appalled, but Martha is firm.  The key is to be used if the human race is suffering without hope; a mercy killing for it."

"That's never an option!" the Doctor snaps.

Martha snaps right back at him.  "Don't argue with me!  I reckon the Daleks need these 27 planets."  She raises her key.  "What happens if it becomes 26?"

"She's good," Rose says admiringly, a 180 from her attitude in Stolen Earth.  Martha, on introduction, is stunned that the Doctor found Rose.  But a second transmission interrupts the healing of the shipper war.

"Captain Jack Harkness, calling all Dalek boys and girls," Jack carols.   It's hard to say if Rose is more shocked to see him still alive or to see her mother behind him.  Mickey and Sarah Jane are there as well.

Jack has his own stop-or-die proposal; he's wired the Warp Star into the Crucible; if they do anything, he'll blow it out of space.

"Where did you get a Warp Star?" the Doctor asks, horrified.

"From me," Sarah Jane says.  She goes on about how there's no other alternative, but Davros is fascinated to see his old foe.  (Sales of "Genesis of the Daleks" must really have boomed after this episode.)

Sarah Jane isn't frightened now.  "Remember?" she spits back at a delighted Davros.  "I've learned how to fight since then.  You let go of the Doctor or this Warp Star, it gets opened."

Rose is thrilled to see her people fighting back, but the Doctor is silent and horrified. Davros is jubilant.  This is the soul of the Doctor - "who abhors violence and never carries a gun... You take ordinary people and fashion them into weapons.  Behold your Children of Time transformed into murderers.  I made the Daleks.  You made this."

It's an incredibly powerful moment, and a theme which I wish they'd dwelled on for a bit longer - but at the same time, it's hardly as though the Doctor invented the Osterhagen key or that the human race, when left to itself, only gathers flowers and knits toilet paper cozies in universal harmony.

Davros twists the knife, saying that he has already seen the Children of Time sacrifice one of their own. It's the first that the Doctor has heard of Harriet Jones' fate.  "How many have died in your name?" Davros asks, and it's a long line of flashbacks to assorted characters who have fallen.  Good thing they stuck to New Who; if they'd done the whole series it would have taken a full day just to air this segment.  They also only show the people who fell fighting for the Doctor and not the ones he killed, which is an even longer list.

David, always at his best in the silent scenes, radiates anger and horror as Davros gloats, "The Doctor.  The one who always runs and never looks back because he dare not out of shame.  This is my final victory.  I have shown you yourself."

Martha braces to use the key.  Jack braces to break the warp star.  But before they can do anything, the Supreme Dalek teleports them to the Doctor and Davros.

At the Doctor's urging, they kneel and surrender.  "Mum, I told you not to," Rose hisses. 

"I couldn't leave you," Jackie replies.  It's great to see Jackie, but hasn't she left behind an infant to go haring after her grown daughter?  No wonder Rose thinks love means never getting more than 20 feet away from  whoever you're with.

"DETONATE THE REALITY BOMB!" Davros howls.

With much CGI and swelling music, something that looks far too much like the Death Star starts to gear up, while Davros shrieks with insane laughter about how nothing and no one can stop him.

Except for human!Doctor and Donna, who are just about to pull a Bad Wolf and vworp their way in to save the day.  It's Caan giggling as the human!Doctor comes running out of the TARDIS with his reversal gun...

Only to be stopped by a bolt to the heart from Davros.  Good plan, poor execution, human!Doctor.  Donna launches out and grabs the gun, to be felled in her turn.  The Daleks casually exterminate the gun into bits.

In a moment stolen straight from reality shows, the tension is randomly held so that Davros can redeliver exposition about the state everyone is in, the music can get louder, and a little more CGI can be thrown in. It's nothing but padding to draw out the moment before the Reality Bomb fires.

The countdown finally reaches "Fire!" - and the power fails.  Donna, the only one not in a spotlight cell and now standing in the middle of the lashup of equipment human!Doctor built, technobabbles about how the feedback loop has been disabled.  Davros tries to zap her again; she throws a lever and his glove backfires.  The Daleks wheel on her; with some rapid playing of levers, their guns refuse to function.  She technobabbles what she's done so fast I can't even follow the words, but the explanation of what has happened to her - two-way biological metacrisis, with her half being activated by the energy bolt, is delivered at a more understandable pace.

Well, more understandable if you're not that demanding in the logic department. 

"DoctorDonna!" the original Doctor says, shouting out to Planet of the Ood.  A delighted Donna drops all the holding cells and orders the "skinny boys in suits" to get to work.  Both Doctors launch themselves back to the TARDIS, but it's Donna who has made the Daleks dance and twirl out of control.  (I hope the guys inside were having fun with that scene!)

Donna couldn't be more pleased with herself.  She's figuring things out faster than the Doctors "because you two are just Time Lords, dumbos!"  It's the bit of human that has given DoctorDonna new perspective that the Doctor(s) doesn't have.

Human!Doctor is delighted as Donna wreaks havoc on the Daleks; the Doctor is surprisingly silent.  Mickey and Jack grab their BFGs.  Sarah Jane and Rose exchange "good to see you"s over the Dalek they're pushing into a wall.  Martha pushes one as well, while the two Doctors and Donna send the planets back.

There's another round of expository technobabble as Donna explains to Rose that the Doctor fed his regeneration energy into his hand, which grew into another Doctor when Donna touched it, and Donna got a little bit of Time Lord in her brain that was unlocked when Davros zapped her.

"So there's three of you?" Rose asks the Doctor.

"I can't tell you what I'm thinking right now," Jack says.  Oh, Jack, don't ever change.

Mickey has his BFG right in Davros' face.  "You promised me, Dalek Caan," Davros protests.  "Why did you not foresee this?"

Nick Briggs wins "most unhinged giggle of all" topping both the Master and Davros as Caan snickers back.  Caan had foreseen the triumph of the Daleks over reality - but he didn't think much of it.  He had engineered everything in order to bring the Doctor in to bring about their downfall.

The Supreme Dalek comes down to take care of business itself, but it only gets one shot - and that at the machine returning the planets - before Jack blows it to smithereens.

The Doctor runs into the TARDIS; there's only one planet left (Earth, natch) but he can figure out a way to tow it through space.  While he's off doing that, Davros pleas to Caan for help, but Caan flops and giggles that he wants the Doctor to end the Dalek empire. 

Human!Doctor hears him and agrees; with a flip of a few switches and a quick burst of technobabble, Daleks start blowing up all over the place.

Surprisingly for a guy who has been fighting the Daleks his entire life, has twice attempted to snuff them out of existence in New Who, and who was willing to wipe his own homeworld out of space and time to conquer them, the Doctor is upset about this.

Back on Earth, the time bubble on the Hub drops as the Dalek explodes.  Before we get any more cameos, we're back onboard the Dalek ship, where the Doctor is pulling everyone back into the TARDIS.  Surprisingly, this includes an offer to Davros, stuck in his chair as the ship explodes around him.

Davros tells him where to stick his mercy.  "I name you forever!  You are the Destroyer of Worlds!"

Again uncharacteristically, the Doctor isn't very thrilled.  I guess he prefers "The Oncoming Storm," on account of that sounding so much friendlier.  Alternatively, he might have been holding out for "Washer of Racnoss Down the Drain," "Destroyer of Gelth,"  or maybe "Eternal Tormentor of the Family of Blood." Or any of the other peaceful, cheerful fluffy-bunny things we've watched him do to races that piss him off.

There's just enough time for Dalek Caan to whip a very deceased equine with the parting line, "One will still die," as the Doctor heads back into the TARDIS.

Inside the shaking TARDIS, everyone is clustered around the console.  The Doctor intends to move Earth back into its proper place, but starts with a shout-out to the fact that Eve Myles played Gwenneth and Gwen.  Torchwood is to throw the rift manipulator open so the Doctor can use its energy, while Luke and Mr. Smith are to harness that power to the TARDIS.  Mr. Smith requires the TARDIS basecode numerals, which the Doctor worries will take too long to get.

"Let me!" Sarah Jane cries, and darts to the monitor to introduce the last cameo appearance: "K-9, out you come!" (I found this a bit gratuitous, but people who were at the public viewing in London said the crowd went nuts when he appeared.)  With K-9 streaming the codes at high speed, long-time extended canon/fanon becomes real canon as the Doctor admits that the TARDIS was intended to be flown by a team.  He stations everyone but Jackie around the console and teaches them how to fly the ship.

The CGI is so pretty and the music so nice (Murray, WHEN do we get that new album?) and the cameos of everyone we know on Earth clinging on or hiding under the furniture are so funny that I almost forget to wonder about how the hell this is supposed to work, what gravitational forces are splitting open the rift, how long the trip is supposed to take (in a sunless void, yet) and just what the mechanics are supposed to be about inserting the Earth back into solar orbit without smacking into something large and hard and in the way, like our own moon.

The TARDIS does fly more smoothly than normal, and not a thing sparks or needs whacked with a hammer.  Both Freema and David break the fourth wall by mugging directly into the camera.  John has said in interviews that everyone was finding it hard to settle down and act while filming this scene because they were all treating it as a big pyjama party of joy.  And in many ways, it is the ultimate glorious fanservice.

It's cheering, laughter, and hugs all around (Donna literally rips Sarah Jane out of Jack's arms) as the Earth snaps back into place.

Enjoy the joy.  Because huge parts of the fandom are pissed off by at least one thing that happens next.

The TARDIS lands somewhere in a park, church bells chiming in celebration.  Sarah Jane and the Doctor are first out and Sarah Jane - having known him the longest and arguably knowing him the best, lands a home truth on him.  "You act like such a lonely man, but look at you!  You've got the biggest family on Earth."  She offers him a huge hug, but then scampers off to be with Luke.

Inside the TARDIS, Mickey is saying his goodbyes to a confused Jackie.  Outside, the Doctor is sonicing Jack's wrist computer, snapping "I told you, no teleport."  (Oh, Doctor?  Why?  And what makes you the judge?)  He also orders Martha to "save the world one more time" by destroying her piece of the Osterhagen key. Both Jack and Martha salute the Doctor (surprisingly, he returns it) before they walk off hand in hand, Jack trying to recruit her for Torchwood.  Mickey runs after them; with his gran peacefully dead and Rose wrapped up in the Doctor, he's decided to return to this world.

For reasons only the Doctor knows, he drops Rose and Jackie off at Bad Wolf Bay.  "Fat lot of good this is! Bloody Norway!" Jackie snaps.  She does tell human!Doctor that she had her baby - a boy - and lets him think it was named after him before she tells him it's named Tony.

And this is where everything starts going pearshaped.

Rose, having gotten back to the Doctor, makes it clear that she has no intention of leaving him again.  The Doctor tells her she has to, and gives her a mission - to heal human!Doctor, who is too "dangerous" to be left on his own.  Yes, the Doctor who killed his own planet to get the Daleks, who was willing to shoot through Rose to kill the last survivor, who has committed genocide several times in New Who, somehow is still upset that the human!Doctor actually accomplished the extermination of the Daleks.

Maybe he's jealous.

Or maybe he's making up a story that Rose will find attractive; that's a popular theory.  Because what the Doctor wants is for Rose to live out her life with human!Doctor and to "fix" him the same way she fixed the Doctor when he was Nine and reeling from survivor's guilt.

"But he's not you," Rose points out.

"He needs you.  That's very me," the Doctor says.

"I've only got one life, Rose Tyler," human!Doctor says.  "I could spend it with you."

The TARDIS makes a warning noise, and the Doctor says he has to go with Donna; the walls between the worlds are sealing up again.  He turns his back on Rose and begins to walk away; she chases after him and demands that both Doctors tell her what the unfinished sentence was that he told her "on this beach on the worst day of my life."  The Doctor starts it, but refuses to finish it.  Human!Doctor whispers in her ear, and after a pause, Rose launches at him in a kiss.  

The Doctor swallows once and turns away, walking back to the TARDIS and Donna.  When Rose hears the TARDIS dematerialize, she breaks the clinch and runs after.  Human!Doctor takes her hand as the Doctor leaves her behind without a goodbye. Rose looks at him.  Neither one is smiling.

Some fans are happy that Rose has a Doctor-like.  Some are appalled that she is stuck with Doctor-lite.  Stephen Moffat drew ire at San Diego Comic Con by saying it was the solution to "getting rid of a slightly clingy exgirlfriend," but he wasn't the only one who thinks that human!Doctor is as much Rose's jailer as her ward, staying behind to make sure that she stays behind and stops ripping apart her family and the walls of reality.

It's an ending that simultaneously supports and sinks a 'ship. 

Next on the chopping block are the Donna fans.  Inside the TARDIS, a gleeful Donna is flying the ship and rattling on a mile a minute when she starts repeating words.  The metacrisis is breaking down; her brain can't handle the Time Lord bits.  Donna knows what's happening, but she's trying to avoid it.  "I want to stay.  I was gonna be with you forever."

She's going to be with him for about another minute.  As she begs "No, don't make me go back, I can't go back, no, Doctor, please, no, no!" the Doctor wipes her mind of all memories concerning him.

Some fans see this as straight-out assault.  Some feel she would be better off dead.  Many point out half a dozen canonical alternatives, starting with the Chamelion arch.  And some feel that the Doctor was also trying to avoid this moment until it came, and then did what he felt he had to in order to save Donna's life.  I'm among the last set, but there are so many alternatives that could have been taken!

In the end, though, it comes down to the Doctor, once more alone, once more filled with grief.  Davies has done wonders for this show - reviving it and riding it to the top of the ratings, for one thing - but I still wonder if he would call it Doctor Woe.

Wilf is appalled as the Doctor explains to him that Donna can't remember anything, that "that version of Donna is dead."  

Then he has to handwave it immediately when Sylvia points out that the whole world is talking about what happened.  For some reason, the Doctor doesn't think this will unlock anything.  (Riiiiiiiight.)  Nor does seeing the Doctor (who introduces himself as John Smith) when Donna wakes up and barrels into the room.

Sylvia more or less throws the Doctor out, but not before he gets in a dig that she should show Donna more appreciation.  As he leaves, Donna is on the phone, laughing off the idiocy that the world could have moved, and nattering about trivia.  Fans make much of her ring flashing light as she moves, wondering if that could be a clue to her memories.  Certainly they can't have been completely wiped, or there wouldn't be anything for the Doctor to be afraid to be remembered.

In essence, Donna has been fobwatched, without benefit of fobwatch.  It does leave a chance of her return.  And in the meantime, so many fix-it fics have poured out of fandom that I've seen the term "fanfixion" for the first time.

The Doctor walks out into the rain.  Wilf asks who he's got, but the Doctor says he's fine.  That special sort of Time Lord "fine" that means "I'm going to paint my bedroom black and listen to Evanescence while I weep."  While David Tennant looks wet, depressed, and pathetic, Wilf promises to look up every night and think of the Doctor because Donna can't.

The Murray Gold score should have been replaced with "Alone Again, Naturally" as a dripping Doctor walks into the TARDIS and wends his emo, lonely way away.  But cheer up kiddies!  The man who brought you this is going to write your Christmas treat!