All five two-part episodes from the 20th series of the BBC crime thriller. Forensic experts Dr Nikki Alexander (Emilia Fox), Jack Hodgson (David Caves) and Leo's replacement Dr Thomas Chamberlain (Richard Lintern) investigate various cases including a serial killer targeting illegal immigrants and the disappearance of a young schoolteacher. The episodes are: 'Identity: Part 1', 'Identity: Part 2', 'Remembrance: Part 1', 'Remembrance: Part 2', 'Discovery: Part 1', 'Discovery: Part 2', 'Covenant: Part 1', 'Covenant: Part 2', 'Awakening: Part 1' and 'Awakening: Part 2'.