Tiermann's World is about to have a very bad day. A Voracious Craw, an immense, space-going worm, is about to consume its landmasses. The Doctor and Martha swoop in to rescue the only people onworld, robotics genius Doctor Tiermann and family, only to discover that things are a little more complicated than they first appear...

Magrs' story sits pretty firmly in the 'knockabout' school of Who fiction. Tiermann's fondness for AI furniture lets Magrs have free reign and some of the novel's best moments come from just that. Barbara the AI Vending machine is a particular great character and the closing scenes, which see the Doctor and Martha caught in a battle for control of the Tiermann's home between Tiermann and the AI fireplace that runs the central computer is huge fun.

That being said, this is a story which doesn't quite know what it wants to be. The AI furniture is played for comic relief whilst Tiermann himself is an absolutely off the shelf Doctor Who villain. Even the Voracious Craw, a creature that could only ever work on the page is dealt with in a manner which seems designed to appeal to a far younger audience than the rest of the book.

Despite these problems, there's a lot to enjoy here. Magrs has a good ear for dialogue and the interplay between the Doctor and Martha is nicely sparky and quick witted. There's a sense, as there is in the best Martha episodes, of her being the Doctor's instinctive if not intellectual equal and there's a lot of fun interaction between the two here.

All in all though, this is a fun, fast paced story that 10th Doctor and Martha fans will find a lot to enjoy in. Tiermann's world is definitely a nice place to visit, although trust me, you wouldn't want to live there...