This is the first time I have ever enjoyed a Doctor Who book so little that I've thought of giving up on the series. Unfocused and clumsy, Earthworld fails to please on many counts.

After traipsing through the pointless Dinosaur Zone, the Doctor, Fitz and Anji are embroiled in the machinations of a corrupt colony governor, some inept terrorists, killer androids and some very psychotic triplets.

This is a book that just doesn't seem to know what it wants to be about... There are hints of themes such as identity crisis and dealing with grief, but these come through only in smatterings, diluted by uninteresting runaround. Whilst these "identity" themes and ideas have great potential, and could well have tied in very powerfully with the Doctors gradually reawakening memories, Jac Rayner has produced a muddle of a plot that fails to begin to do justice to these ideas.

There are hints that the book will turn out to be about the question of the androids' sentience, but this theme never materialises. There are hints that it's the story of the "terrorists", but they're all but abandoned after the triplets appear. About two-thirds through, the book decides to be about the terrible tragedy of the triplets, and everything before that is suddenly strangely unimportant.

A lot of the devil is in the details here. The Association for New Jupitan Independence is one of several overblown and indulgent "jokes", and the plot seems to fairly turn cartwheels to incorporate it. There's no sense of the population of the colony at all, giving little background to the action. Fitz casually makes jokes using 1990's references that, as a sixties character, are just plain wrong for him.

I found his character dreadfully handled as a whole in the book. He has a sudden crippling identity crisis for absolutely no reason - either in terms of cause, or in terms of what it does for the overall story. This sub-plot is tied up in an almost offensively twee and shallow piece of physchobabble, seemingly as random as his breakdown was to start with.

It's only with Anji that Jac Rayner really seems to settle down and almost produce the goods. Anji's grief for her boyfriend, who died in Escape Velocity, is not forgotten. A rather poignant trick reminds us of her mourning - she composes emails to him throughout the book. Apart from the rather dubious suggestion that Anji types her darkest secrets on a palmtop whilst in the thick of the action, this device works well and is remeniscent of Bernice Sumemerfields Diary entries.

I struggled through the book, hoping it could pull something out of the hat, but although there was a suitably cathartic finish for the major characters, it had lost me a long time before. Perhaps it was simply a case of trying to do too much at once, but the tone seemed uncomfortably stuck between wistful whimsy and half baked psychological drama, and the plot veered to wherever the tired set pieces and cod psychology required it to go.