The Doctor was making his way around, prodding at things with the tip of his umbrella, wiping his finger along the pipes and grimacing at the grease. He’d not been very forthcoming about where they had landed. All Ace knew is that it was London and the 1950s.
This is the culmination of the arc of Seventh Doctor novels by Mike Tucker and Robert Perry, the previous stories being Illegal Alien, Matrix, Storm Harvest and Prime Time. I really enjoyed this, as I really enjoyed them all, and I've realised that this sequence is one of the unsung successes of Who spinoff literature.
The story is suitably complex; the Doctor investigating Ace's murder, even though she is still alive; confused astronauts arriving from another timeline; cyber-technology and giant ants infesting London. There is sensawunda and emotional intensity. There is homage to Quatermass (and perhaps one or two Tuckerisms). I think I couldn't recommend this to readers, even Who fans, who had not read the previous four in this mini-series, but I would warmly recommend reading the whole lot.
Next up in this sequence: The Algebra of Ice, by Lloyd Rose.