In England, 1954, Luke Fitzwilliam, arriving from Nigeria, meets Miss Pinkerton, who reveals her suspicion of a serial killer in her village. When she is killed on her way to report her suspicions to Scotland Yard, Fitzwilliam feels compelled to investigate the deaths in Wychwood. Uncovering hidden tensions, he teams up with Lady of the Manner, Bridget to find the killer before more lives are lost.

As Wychwood is shaken by another death and murder rumours spread, Luke Fitzwilliam confronts his prime suspect, only to see his theory crumble. As Fitzwilliam questions whether he's the right person to take on this mystery, another body is found in the grounds of Ashe Manor. Despite the rising tensions, Lord Whitfield insists on proceeding with his and Bridget's extravagant engagement party.

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?