Episode 2

A gunman is shooting uniformed police officers, one after another, and he has left word that there will be more unless his terms are met. Luther's response is not subtle. He goes on television and taunts the killer, hoping to make the man angry enough to come after him instead of the ranks. It is the sort of gamble that looks reckless from the outside and probably is. And it is exactly the sort of move Luther makes without blinking.

The investigation runs alongside a second, quieter problem. Alice Morgan has been digging into Luther's past, and she is not doing it for his benefit. She makes it clear she will tell Zoe what she has found, and the threat sits in the back of the episode like a timer nobody can switch off. The city is full of a man with a rifle, and Luther's own house is the one place he cannot defend.

Neil Cross wrote this one, Brian Kirk directed, and the supporting cast keeps the world properly populated. Steven Mackintosh's DCI Ian Reed and Saskia Reeves's DSU Rose Teller work the case at Luther's shoulder, Warren Brown's DS Justin Ripley does the legwork, and Indira Varma's Zoe moves through her own life with the marriage cracking behind her. Sam Spruell's Owen Lynch, Louise Rose's Corrine Day and Geoffrey Lumb's PC Steve Gorman all earn their screen time, and Paul McGann's Mark North is there to remind Luther that other people get to be happy.

It is a taut hour that holds two threats side by side: the stranger with the gun and the woman who knows too much. Luther is used to being the smartest person in the room, and the episode is partly about what happens when someone else decides to play the same game with him. The taunt on television is the moment the show says what it thinks of him, a man who would put himself in the crosshairs on purpose.

The ending leaves Alice's file unopened, which is its own kind of threat. Some investigations you win, and some you just survive.