Having enjoyed all of Perry and Tucker's previous Dr Who books, I was looking forward to this one - but was very disappointed. I had trouble concentrating on the book, and got confused about which character was which, and whose side they were on. There was so much double-dealing, and double characters from different dimensions, that I, frankly, got lost. That said, the book is not a complete disappointment: these writers really know how to capture the personalities of their "dream team" of the 7th Dr and Ace; they keep things moving at a cracking pace; the setting, rainy London of the late 50s, is well established; and they can perfectly create a real "Dr Who" atmosphere, complete with four-part structure and edge-of-your-seat cliffhangers. The problem, for me, with this book was its plot, which I found confusing and unengaging. I still think this novel is worth your time; but for a really 5-star 7th Dr and Ace novel, try the same writers' "Storm Harvest" - you won't be disappointed!