Mantrap

Dempsey and Makepeace go undercover to find the mastermind behind a series of jewel heists, and the closer they get to the source, the clearer it becomes that they are the next targets. The trap, when it springs, involves jewels and bank robbers who set it to even the odds, and the pair are in genuine trouble. The unexpected lifeline comes from a boxer Dempsey once sent to jail, who owes him nothing and helps anyway. The reveal catches them at their most exposed, and the boxer's help arrives at the last moment it can.

Murray Smith wrote it, Roger Tucker directed. The guest cast is marvellous: Christopher Benjamin, one of the most familiar faces in British television, is Sam Powell, with Barbara Young's Miriam Powell and Thelma Ruby's Mrs. Lupin around him. Christopher Reich's Mick Ryan, Jonathan McKenna's Mick Walsh and Michael Watkins's Danny Walsh supply the criminal muscle, and Cory Pulman and Heinz Bernard round out the list. It first went out on 25 October 1986, and Murray Smith and Roger Tucker were both working on their second episode of the season, which gives the hour a settled, confident feel.

And the twist of the hour is the boxer's help, which gives the episode a moral point it never hammers home: the people Dempsey has put away are not all grateful for the experience, but some of them remember being treated fairly. It is a small grace note in a plot full of twists, and the show trusts the audience to notice it without having it pointed out, and the plot is allowed to take its time as each piece of the trap clicks into place.

It is a satisfyingly complicated hour, classic caper machinery with a debt of honour at its centre, and it shows the show's gift for making the underworld feel like a village.