A boat loaded up with clothes and music is spotted floated down The Thames unmanned, suspicions aroused, a grim discovery is made.
A cracking episode, it has a thoroughly vintage, early series feel, it's very original, very gritty, it doesn't feel like any other episode.
Writer Julian Jones was clearly having a bad day when he thought of the plot here, it's great, but it is so bleak, no single lighter moment to speak of.
It's about time we get to see Uncle Bob out and about involved in the action, there's been so much of a CID focus lately, he's been hidden away, as always he's great, and straight to the point.
9/10.