Faced with two false confessions and numerous suspects after a despised civil magistrate is found shot in the local vicarage, Detective Inspector Slack reluctantly accepts help from Miss Marple.

Watson and Crick race to find the structure of DNA before Linus Pauling, Maurice Wilkins, or Rosalind Franklin can find the key to unlocking the secret.

Two bored twentysomethings buy a Vauxhall Cavalier kit it out with a siren and spend their evenings masquerading as police officers in this Screen One TV movie

The TARDIS attaches itself to a space liner after Turlough, still under the Black Guardian's influence, damages its controls. The Doctor and Nyssa meet two space pirates, Kari and Olvir, who have come on board the liner in search of plunder, while Tegan and Turlough get lost in the infrastructure. The liner docks with what appears to be a hulk floating in space. This is Terminus, which claims to offer a cure for Lazar's disease. It is crewed by armoured slave workers, the Vanir. The cure is administered by a huge, dog-like creature known as the Garm. Nyssa, who has contracted the disease from sufferers transported aboard the liner, discovers that the cure - involving exposure to radiation - does actually work.

Inmates fight, pair off, try suicide and attempt escape at a British reform school for girls.