Once Bitten

The cloth warehouse has been robbed before, and the owners have decided not to let it happen again. The answer, as they see it, is dogs: several vicious ones, set to guard the premises. For a while the arrangement works. It is the sort of security that holds until somebody cleverer comes along. But then somebody turns up who can talk to the dogs, and the security that was meant to stop thieves becomes a thief's best tool.

The episode has a lovely central idea, and it runs with it. The dog whisperer nearly pulls off a daring robbery by making the guards his own, and the task force is left trying to investigate a crime scene where the only witnesses are barking. A dog whisperer is not the usual villain of a police procedural, and the episode makes the most of the novelty. Barlow, Watt and Hawkins are all on the case, with Sgt. Evans and PC Snow working the ground and PW Det. Con. Forest new to the ranks. Walter Gotell's Cullen looks on, and the force's own four-legged asset, Radar, gets his moment, which feels only fair given the opposition.

Tom Chadbon plays Andrews and Michael Brennan plays Collins, the pair at the centre of the plan, and the episode enjoys the comedy of humans being outsmarted by a man who simply likes dogs better than people. It is a heist story told with the animals on side, which gives the whole thing an agreeably different flavour. Elwyn Jones wrote it, and Simon Langton directed with a light touch that suits the material.

It is a smaller, more playful entry than the season will mostly offer, and none the worse for it. The episode knows it is a lark, and it plays the lark straight. The title sets the tone: the owners have been bitten once and are determined not to be bitten again, until they meet a man who makes the whole arrangement look foolish. The dogs, for the record, were doing their job. The people were the problem.