Errors

Ann Barclay is an unlikely drug mule, which is exactly why she is being arrested in the first place. She is picked up at the local pub carrying something she should not be carrying, and the length of the sentence hanging over her is serious enough that Watt and Hawkins start applying pressure from the moment she is brought in. The episode's title is a quiet warning. Somewhere in this case, somebody has made a mistake. Arrests like this look routine from the outside, which is usually when they are at their most dangerous.

The interest is in watching the pressure work. Watt and Hawkins are not cruel men, but they are certain men, and the interview room scenes here are the heart of the hour. Kate Coleridge plays Ann with a guardedness that keeps the audience guessing about what she knows, and she does not crack easily, which the episode respects. The supporting ranks do their usual work around her: Evans, Snow, Knowles and Nesbitt, with Gillie Gratham as WPC Reed and John McKelvey as Tompkins.

Elwyn Jones wrote it, Geraint Morris directed, and the episode opens the new season in confident form. The pub arrest feels small at first, the way these cases often do, and the show is careful to let the stakes climb without ever raising its voice.

"Errors" is a solid, contained hour about the gap between what the police think they have and what they actually have. Ann Barclay is the unlikely centre of it, and the title keeps nudging at the idea that the biggest mistake in the case may not be hers. It turns out to point at the police as much as at Ann, and that is where the hour gets its sting. It is a good start to the run, modest in scale and quietly assured, the sort of episode that reminds you why the show worked.