9pm PARTNERS IN CRIME - Crime Drama - Agatha Christie's crime-fighting duo, Tommy and Tuppence Beresford, solve mysteries and search for enemy spies in 1950s Britain.
N OR M? Part 1 - Tommy is sent on a secret mission to discover the identity of Soviet spy staying at a seaside guest-house; Tuppence refuses to be left behind.
A British scientist, Gilbert Worthing, who was working on a top-secret prototype for a nuclear bomb, has gone missing from a military base in Cromer, along with his work. All Tommy knows is that the perpetrator is staying at the nearby Sans Souci guesthouse and is most likely a Soviet superspy code named N... or is it M? Tommy must travel to Cromer, disguised as a birdwatcher, in order to identify which guest at the Sans Souci is holding the British government to ransom. Tommy and Tuppence must learn to work together again if they are going to identify the Soviet spy, save the missing scientist and discover the location of the missing bomb before half of Norfolk is obliterated.
10pm NEW TRICKS: Old School Ties - Crime Drama about a police unit, made up of retired detectives and a long-suffering boss, looking at unsolved crimes.
When the body of young PE teacher Jason Bowe is discovered in woodlands adjoining a prestigious boarding school, UCOS are asked to investigate the case quickly and discreetly. However, with the school busy preparing for a visit by prominent MP Geoffrey Parks, its headmistress is less than happy about the UCOS team's presence there.