Schooled in Murder

Somebody killed a dairy worker at the factory that makes the world-famous Midsomer Blue, using a full-size round of the stuff the way another show might use a cricket bat. The factory is the sort of beloved local institution the county is quietly proud of, right up until the moment it becomes a crime scene. The scene is exactly as strange as it sounds, and the team has to investigate it without so much as a smirk, which is the real challenge.

Barnaby and Jones treat the absurdity the only way professionals can: they ignore it and do the work. The dairy's workforce and its families come under the microscope, from Hayley and Gregory Brantner to Beatrix, Oliver and Poppy Ordish, with Debbie Moffett somewhere in the middle of it all. Cheese, it turns out, brings out strong feelings in people, and the inquiry has to follow them through every family involved. Barnaby's method, as always, is to treat everyone the same until they give him a reason not to.

Hattie Morahan's Hayley Brantner, Patrick Robinson's Gregory Brantner, Lucy Liemann's Beatrix Ordish, Richard Dillane's Oliver Ordish, Eloise Webb's Poppy Ordish and Martine McCutcheon's Debbie Moffett fill out the suspect list, with Fiona Dolman's Sarah Barnaby and Tamzin Malleson's Kate Wilding in the usual orbit around Neil Dudgeon's Barnaby and Jason Hughes's Jones. Lisa Holdsworth and Caroline Graham wrote it, Andy Hay directed.

The episode knows what it is: a daft premise played with a straight face, and that combination has carried a lot of Midsomer hours. The cheese is a gimmick with a reason, the motive turns out to be entirely human, and by the end you'll never look at a cheeseboard the same way. And somewhere in all the dairy there's a proper murder to be solved, which the episode never forgets. It's the kind of hour people describe to friends with a disbelieving laugh, and it earns that.