It's been a year since Philippa "Flip" Jackson found herself transported by Tube train to battle robot mosquitoes on a bizarre alien planet in the company of a Time Lord known only as "the Doctor". Lightning never strikes twice, they say. Only now there's a flying saucer whooshing over the top of the night bus taking her home. Inside: the Doctor, with another extraterrestrial menace on his tail — the Daleks, and their twisted creator Davros!