With a teen-aged daughter who needs medical care single mother Sally Wilson is thrilled when lawyer Taylor tells her that a Mr. Smith has left her five million pounds. However there is a condition,which a horrified Sally,playing Smith's CD,finds is that she must kill Richard Bury, a man who 'deserves to die' and who recently killed a prostitute. Sally wants to alert the police but her ex-cop boyfriend Mark talks her into getting more details. Whilst Simon Harris,who runs a homeless charity,gets an offer similar to Sally's, Tori Sturridge,who stabbed complete stranger Scott Bradley,is mown down by a hit-and-run driver.Sally suspects Bury but,staking out his house,realises that she is part of a chain where each successive killer is themselves murdered.