Law

A teenage girl is found murdered, and the trail leads the team to the travellers working the fairground nearby. It is a case that asks the police to move through a community that does not much want them there, and the early work is all about listening before judging. Their welcome for the polis is short, and their answers come in their own time. The fairground families, the Donnellys and the Bucklands, have their own loyalties and their own ideas about strangers with notebooks.

The episode spends its time on the people rather than the procedure, which is the right call. A death like this pulls at every thread in a small community, and the writers give the extended Buckland family room to breathe: Samuel, Elijah, Noah, Vancy, each with a stake in what happened and each with something to protect. Sarah Donnelly and Rab Donnelly anchor the other side of the story. And the investigation moves slowly through them all, revealing details about people before it reveals answers. The show trusts its audience to keep the family straight, and the patience is rewarded.

Glenn Chandler and Mike Cullen wrote it, Ian Madden directed. Blythe Duff's DS Jackie Reid does much of the patient work, with John Michie's DI Robbie Ross, Alex Norton's DCI Matt Burke and Colin McCredie's DC Stuart Fraser behind her. Mirin Barr is Sarah Donnelly, Alan McHugh is Rab Donnelly, and the Buckland family is played by Andrew Lee Potts, David Bradley, Garry Cooper and Julie Duncanson.

The cleverest killer in Glasgow is not required here. This one is about how a single death unravels the lives around it, and it moves at the speed of a fairground: loud in patches, patient underneath. The mystery is served, but the people are served first. That is a fair trade.