One Day a Lemming Will Fly (1)

A missing boy becomes a dead boy, and Manchester decides who to blame before the police have finished looking. Tim Lang is found hanged in a wood, and the crowd outside the station has already settled on his school teacher, Mr Cassidy. The mood is ugly, and the pressure lands on everyone: the squad, the family, and Fitz, who gets pulled in whether the constabulary likes him or not.

Billborough is waiting for his child to be born, which puts him at a desk with his nerves already stretched. Fitz moves through the edges of the case, talking to Judith, watching the city turn. Linda Henry's Mrs Perry and Frances Tomelty's Mrs Lang bring the grief in close, while John Vine's Lindsay and the rest of the squad keep the investigation grinding on. Wesley Cook's Tim is gone before we really meet him, and that restraint is part of what makes the grief feel real. The Lang family's grief is kept off the front pages of the story, which makes it land harder.

McGovern wrote it, Simon Cellan Jones directed it, and the episode is a study in what a community does with its anger before the facts arrive. The mob outside the station does not want justice. It wants a name to shout at, and Cassidy is the name they have chosen. The episode keeps its cameras at street level, where rumour moves faster than fact. The anger is real, and so is the danger it creates for a man who may have done nothing.

The investigation starts in a wood and ends in a crowd, and the journey between the two is the episode. Whether Cassidy is the right name is what the second part has to answer. And the show is in no hurry to let anyone off the hook, least of all the audience.