Berserker

Illegal bodybuilding drugs laced with mind-bending additives are killing people around Glasgow's muscle scene, and the Maryhill team is racing to find the source. They call in a famous chemistry professor from the university for help. The question hanging over the episode is whether he is helping or whether he is the source. The trail runs through gyms and dealers before it gets anywhere near a laboratory. The drug is a cocktail of ambition and carelessness, which is a very Glasgow combination.

It is a decent hook, and the script keeps the professor just ambiguous enough. But the professor stays the hinge, and the episode runs him for as long as it can. The deaths are messy, and the victims are the kind of people who thought they were buying an edge. There are bodies before the team is properly in gear, which sets the pace for everything after.

Bodybuilding as a crime setting gives the show something it rarely uses, a world of men who have built themselves into something fragile. There is a particular sadness in that, the bodies that were meant to be armour turning out to be the weak spot. The episode is a drug story with the glamour stripped out, which is how Glasgow does it. The show has always liked a case you can smell before you can see it.

Glenn Chandler and Phil Ford wrote it, Richard Holthouse directed. James MacPherson, Blythe Duff and Colin McCredie lead, with Iain Anders as McVitie, George Rossi as DI Pete Skinner and Robert Robertson as Dr Andrews. David Robb's James Mitchell, Cameron Jack's Daniel Mitchell, Katherine Igoe's Juliette Curtis and Valerie Gogan's Linda Meddows round out the supporting cast.

The chemistry is a bit convenient, but the tension holds. It is not the show's deepest case, but it is one of its most restless. The bodies are the argument; the professor is the suspense.