Two English brothers with different, clashing personalities become live-in home renovators for a notoriously finicky couple with strong opinions.

Harry Sands is a self made man, happily married with two children. When he learns that his daughter has gone missing in Istanbul, he flies out to find her. To Harry's horror, he discovers from Olivia's best friend, that the two of them have been working as nightclub dancers and not as the charity workers like Harry was led to believe. So begins the hunt for his missing daughter and a journey that turns into a nightmare as Harry is forced to face his own prejudices and mounting paranoia....

Quirky stranger Donovan (Colin Firth) blows into the Scottish village of Port Clyde. There, he rents a room with the Pannick family and ingratiates himself into their lives. Lucy (Katy Murphy) is the long-suffering matriarch of the clan, caring for her senile grandmother (Liz Smith) and mentally disabled brother, Sandy (David Brown). When the town cancels Sandy's train route to school, Donovan suggests starting their own bus line. They do, much to the consternation of local officials.

Based on the chilling novel by Nicci French, a police officer struggles to unravel the murderous plot of a methodical stalker targeting three women.