I thought there was a very good performance by an actress I have never seen before - Sharon D Clarke - who played the mother of a key witness who is on the run. Oh, apparently she's a regular in Holby City, so I suppose a lot of people know her already. She played a touching role - a strong brave person who was obviously not used to being intimidated, but was scared almost out of her wits by Spall, who plays a psychopathic little herbert.
Overall the acting is good, and the direction is very arty, like a play. It's obviously one of those shows where the BBc are being self-consciously classy, and the police/drug gang parallelism is inspired by The Wire, but what the heck none the worse for that. There has been some significantly good drama on BBC lately, and more to come, which is great.