It has to be said that some of the Target novelisations of the Sylvester McCoy stories could be a bit hit an miss. Some were just basic retellings of the script with a little extra detail, and others which really fleshed out the stories and the characters wonderfully. This book falls into the latter category. Ben Aaronvitch was around the Doctor Who production office a lot during the two series he was there as a writer, and thus had insight into the character of Ace, and Andrew Cartmel's grander concepts of the Doctor. The story of Rassilon, Omega and The Other, the firebombing of Ace's friend Manisha's house, Davros' debates with himself about the racial purity fo the Kaled race, the exerpts from Kadiatu Lethbridge Stewart and Dalek name for the Doctor are all interwoven throughout Who continuity afterwards, in the books, audio and even in the new series.
That's before he gets to giving some of the characters real depth and backstory. The love affair between Group Captain Gilmour and Rachel Jensen is brought wonderflly to life here in a way that's barely hinted at on screen. The passage which describes the action from the internal point of view of the Daleks are very cleverly done, and Aaronvitch shows that he had a real understanding of the depth of characterisation of the Doctor that both Cartmell and McCoy were aiming for. Even the legendary Terence Dicks was never able to go this far.
In short one, of the finest novels in the Target range by the author that wrote the script for it in the first place.