A full blown riot in St Davids means that some prisoners have to be stationed at Mount Thomas and it's not going to be easy with lots of problems. To make matters worse, Tom has already gone fishing, so Tess is in charge.
Tom and PJ head off for a fishing weekend - leaving Tess in charge for the first time. All seems to be going smoothly until some prisoners prove they are a violent, unruly group which takes Tess to the edge. The bashing of one of the inmates uncovers a web of deceit and proves a vital clue to the identity of a murderer.