Kaye Whiting went to buy a birthday present and didn't come back. She isn't dead, or physically injured. But she is alone and very, very scared. Fifty miles away in Cambridge town centre a deeply disturbed young woman is standing by a payphone. She knows she often feels compelled to do harmful things and is driven by a desire to make a call. DC Gary Goodhew is one of the detectives assigned to find Kaye and when her body is discovered the only clue to the potential murderer is a woman's voice on his answerphone saying, 'Kaye isn't the first and won't be the last...'