On the train to London, Luke Fitzwilliam meets the elderly Miss Pinkerton, who confides in him that a killer is on the loose in her quiet village. When Miss Pinkerton is struck down on her way to Scotland Yard, Luke faces a moral predicament.

As Wychwood reels after another tragic death, the discovery of a crucial piece of evidence blows the investigation wide open and leaves Luke Fitzwilliam questioning who he can trust.

The wedding is called into question when Bridget makes an explosive confession to Fitzwilliam. As both of their futures hang in the balance, the discovery of a new piece of evidence blows the case wide open and forces Fitzwilliam to re-examine everything. With time running out, and suddenly unsure of who he can trust in Wychwood, will Fitzwilliam be able to stop the killer before it's too late?