Nicola Walker (Last Tango in Halifax) and Sanjeev Bhaskar (Indian Summers) star as police officers investigating the cold case murder of a boy whose diary implicates four seemingly unconnected couples in a thriller that The Guardian (UK) hailed as “so much more than a satisfying murder mystery.”

Aired: 5/13/2018 | 1:22:41 | Expires: 5/13/2022 | Episode