Mad Dog

Animal rights campaigners free a group of dogs from a laboratory, and the gesture is meant to be liberation. But the one thing they miss is that one of the animals is dangerously ill. That oversight turns an act of protest into a public danger, and the fallout lands on a children's birthday party that becomes a nightmare for Maggie Forbes. Balloons and cake, with a sick animal loose in the middle of it all. The campaigners meant well, which makes the damage harder to be angry about and no easier to clean up.

The investigation that follows is a containment job as much as anything: the escaped dogs have to be found before the ill one does real damage. The clock matters more than motive, and the team works the streets in a hurry. The trail starts at the laboratory, and every hour that passes makes the search more urgent. The police work is a race rather than a puzzle, and it suits the show's plain style.

The episode is built on a simple and effective dread. Everyone understands what a frightened, sick animal can do at close quarters, and the script spends its time closing the distance. The birthday party is the episode's best stroke, because it turns an abstract danger into a room full of children. Subtlety is not what it is after, and the episode is better for it.

Terence Feely wrote it, Peter Cregeen directed. Jill Gascoine heads the cast as Maggie, with William Marlowe's Russell, Paul Moriarty's Jake Barratt, Kevin O'Shea as Peter Phillips and Michael Graham Cox as Jack Slater. Andrew Burt plays Doctor Davies, Louise Jameson is Emma Saunders, Lynsey Baxter plays Sally Wyatt, Robin Hayter is Lennie Muldoon and Larry Martyn appears as the minicab driver.

Domestic chaos and serious police work, side by side, is this show's home turf. The dog at the centre of it all is the best actor in the piece, which is not a criticism of the humans.