Sam Tyler still feels like an outsider in 1973. Or, as Annie Norris puts it, ""You have more issues than Life magazine."

The squad gets a call from a student radical terrorist group known as The Weather Underground, claiming responsibility for "the bombings".

The first bomb goes off at Glennister's bar, killing 5, including 3 cops. All three were close friends of Lt. Gene Hunt. They were planning to watch the "Revenge of the Broken Jaw" prize fight together later that evening.

Sam views a film of a WU demonstration rally, and hallucinates that the group's charismatic and very much deceased leader, RodneySlaven, is speaking directly to him. Slaven as distinctive, mesmerizing mismatched eyes... like David Bowie, Annie says.

The detectives arrest a college professor, Patricia Olsen for suspicion of involvement. She's hard-core anti-cop, and all of her "A" student are members of the WU. She  resists the interrogation every step of the way. Soon, Olsen's husband, Dr. Richard Olsen, and their daughter Laura arrive at the precinct.

Meanwhile, the detectives are notified that the bomb squad is called out to another situation. Another cop -- also a friend of Hunt, is trapped in his car, with a bomb wired to the ignition. If he lets go of the key, or if completes the switch, the bomb will explode. Hunt puts himself in the middle of it, and won't leave.

Back at the precinct, Sam reviews the film again. Annie comments on Slaven's mismatched rock star eyes, and that he died of a drug overdose a year earlier. Annie reviews Slaven's file and notes that he died of a pharmaceutical grade drug, not heroin, exactly one year ago. Annie notes that it's odd that on the anniversary of Slaven's death, four cops are killed

Sam is certain that there is another bomb, and that Hunt is the target...

This politically charged episode is heartbreaking in some respects. It explores the ramifications of domestic terrorism and the passions that drive it -- which are, in sometimes misguided. Hunt loses several of his friends, and a family is ripped apart over jealousies and deception.

This is also the episode in which Sam seems to come to terms with his situation. He tells his shrink, "I'm ready to start living here, in 1973... but as long as I'm here, I can never ever stop trying to find my way home." Sam is obviously developing a fondness for Annie.

The writing, as always, is excellent, and is of the caliber that makes one sad that this will be the only season. This show provides an interesting filter for looking at today's problems through the lens of history is enlightening. Naming the cop bar "Glennister's" is a nice touch, a nod to the actor who played Hunt in the BBC series.

(Original air date: 3/4/2009)