In Death In Disguise Detective Chief Inspector Barnaby is called into look at a dead guy at a new-age commune. The guy might have just fallen down the stairs but Barnaby is always Mr Plod and he gets right to work. The commune and the members are all pretty odd characters. Sgt Troy isn't too keen on the commune members but Barnaby has a more measured response to them. He says it's a generational thing. They two detectives work fairly well together but Barnaby is often sarcastic when Troy mentions something pretty obvious. There's a second death and this time it's murder. Find out who did it at the link above.
I've decided to use the numbering of the episodes that are listed on the Wikipedia which has the shows in production order. They were often aired out of that order. This episode first was shown on ITV May 6 1998. It was the 3rd made but the 5th aired.