Saturday, 7.30pm, ABC1 The old dogs of the Unsolved Crime and Open Case Squad return for a 10th season of New Tricks. This BBC hot favourite police procedural might more accurately be called old tricks, since the central conceit is hoary detectives using their experience and worldliness to solve cases others couldn’t. This is no less true of the actors themselves. Dennis Waterman and Alun Armstrong (pictured) and Denis Lawson bring wit, range and sheer likability to their offbeat characters. Amanda Redman provides the glamorous foil as Detective Superintendent Sandra Pullman, trying to keep her charges in line but barely succeeding. This first part of a two-part special takes the team to Gibraltar, seeking to unravel the mystery of two murders committed years apart with the same weapon. The Falklands War serves as a historical backdrop, reviving the era’s slang, including ‘‘ squaddies’’ and ‘‘ Argies’’, though contemporary themes such as online gambling are also introduced. Serious issues including alcoholism, professional regret and the fear of retirement are balanced with the gentle age-based humour this show does so well. It’s wise not to take shows this long in the tooth for granted. One much-loved character will not survive the season.