It starts off with one of those comedic eccentric characters whose wife has ran off with someone else.
Arthur Biddle (Norman Bird) tells Frank Marker that his wife has been seen with a disreputable chap called Brian Stafford.
Only when Frank finds Brian, he sees a withdrawn loner with no middle aged woman in sight.
The penny drops when Miss Price comes storming into Frank's office. She is Brian's parole officer. He was in for manslaughter for killing his wife. The victim being Arthur's daughter.
Now Arthur wants revenge as the state did not execute Brian, he was out in 15 years. No one understands the pain Brian feels.
Written by the Bristol boys, Bob Baker and Dave Martin who found fame as writers of Doctor Who. They were the creators of K9. Baker also wrote for Wallace & Gromit.
This is a darker story but the writing keeps everything too simplistic. Brian hints that his wife was malicious. While he was a soldier serving in Cyprus, she was with other men.
In a sense both Arthur and Brian are pathetic figures. Arthur never got over the death of his daughter, even his wife eventually left him. Her daughter's room is still a shrine.
Brian is meanwhile is sanguine about his fate. Even if it means death from Arthur's hands.
It is left to Frank to come to the rescue as the police are of no help.
There is some mirroring between Frank and Brian. Both served time and Frank also looked lost when he was released. At least Frank fought back and he was inside for a less serious crime.