Orchis Fatalis

A trail of dead bodies, all of them connected by a shared enthusiasm for rare orchids. That is the puzzle dropped on Barnaby's desk this week. But even by Midsomer standards, it is an odd one. Most village murders at least pretend to be about sex or money. This one is about flowers, flowers with Latin names at that, the sort you need a greenhouse and a small fortune to keep alive.

The hunt takes Barnaby and Sergeant Dan Scott through the damp, watchful world of collectors, where a prize specimen matters more than a friendship and nobody shows their hand twice. Dr George Bullard turns up to add medical detail, Joyce holds the fort at home, and the suspects are suitably peculiar: Madeline Villiers, Jimmy Fong and Margaret Winstanley circle the prize blooms with very different ideas about who deserves them, while Henry and Deborah Plummer watch on with the fixed smiles of people already counting their inheritance. Barnaby, who has met enough harmless-seeming people to know better, takes his time with each of them.

Terry Hodgkinson wrote the script with Caroline Graham, and Peter Smith directed. John Nettles leads as Barnaby, John Hopkins as Scott, with Marty Cruickshank as Madeline Villiers, Stuart Ong as Jimmy Fong, Harriet Walter as Margaret Winstanley, Richard Attlee as Henry Plummer and Amanda Harris as Deborah Plummer. Barry Jackson, Jane Wymark and Laura Howard complete the regular side of things. It is a tight, old-fashioned whodunit, the kind the series does best, and the botanical setting gives it a freshness that offsets the formula.

The title is no accident: 'fatalis' is Latin for deadly, and the episode enjoys the joke. Whatever you collect in Midsomer, someone else will want it badly enough to kill for it, and rare orchids are just the prettiest excuse the show has found yet. The flowers themselves never hurt anyone. It is the people who grow them you have to watch.