All five two-part episodes from the 18th 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 murderous sniper picking people off at random, the death of a man who's pushed in front of a train and the assassination attempt of a wealthy Russian businessman. The episodes are: 'Sniper's Nest', 'Falling Angels', 'Protection', 'Squaring the Circle' and 'One of Our Own'.