Two ex-army men track down their former sergeant in his remote country shack hideaway - with the sole purpose to torment him and exact revenge for what they see as his betrayal seven years earlier, which led to them being kicked out of the armed forces and imprisoned for a crime they say the didn't commit.
This is a rather uncomfortable watch, and you can see from the start it's not going to end well. The action pretty-much all takes place in the same room, so there's little space for creating any filmic atmosphere or much in the way of breathing space away from the dialogue.
It's great seeing John Thaw - just two or three years before he found fame as Jack Regan in The Sweeney, and you can certainly see elements of his best-loved character here, although he comes across as fairly humorless and unsympathetic here.
As with most of the stories in this series, it's quite jarring and sad, and you wonder how it's all going to resolve itself.
It's probably one of the weaker stories in what was quite a patchy series at best - but more of interest these days for its nostalgia value, and seeing familiar actors in earlier roles.