It is almost unthinkable that a single maniac would murder two women miles apart on the same day. Yet someone followed Carol Garner home from the train station and strangled her to death in front of her three-year-old son. And, afterwards, Ruth Murray died in a similar manner. The evidence is leading Detective Inspector Tom Thorne to a stunning conclusion: there isn't only one serial killer on the prowl, but a pair of them, working in tandem. And any corpse that turns up in the future just might be accompanied by a second. To stop them both, Thorne must catch a man whose need to manipulate is as great as his need to kill; a man who will threaten those closest to Thorne himself; a man who will show him that the ability to inspire terror is the deadliest weapon of all.