Things are not going smoothly in the Camden murder investigation team in north London. No sooner have they caught the notorious serial killer dubbed the Night Creeper than he finds an alibi, is poisoned, gets hijacked from the ambulance and vanishes with his kidnappers. DI Tina Boyd, in charge of tracking him down for a second time, is obsessed with revenge and struggling with a drink problem. Worse, undercover cop Sean Egan is plunged into the most hazardous mission of his career, during which he is beaten, imprisoned, shot, set fire to . . . And all the time the tally is rising, not just of victims, but of killers too  six by my reckoning, but I may have missed one. Still, Camden's problems are the reader's gain in this vibrant, engrossing and constantly surprising crime novel. The pace never lets up, and in spite of some fairly lurid violence  Kernick is particularly good on the details of hand-to-hand fighting  this book has a heart, as well as gore galore.