2006: The case is thrown into disarray when someone with important information is found murdered. Tony is horrified as he begins to realise that someone close to him isn't the person he claimed to be. In the present day Julien is intent on reinvestigating the links between the dead witness and Oliver's disappearance. The stress of the reopening of the case starts to take its toll on Emily and Mark's relationship.
Elenco: David Morrissey , Keeley Hawes , Abigail Hardingham , Tchéky Karyo , Anastasia Hille , Roger Allam , Laura Fraser , Lia Williams .