Double bill of British crime dramas. In 'Booby Trap' (1957) Professor Hasdane (Tony Quinn) creates an exploding pen but mistakenly leaves his new invention in a taxi where it is discovered by Sammy (Harry Fowler), an employee of seedy nightclub owner Mr. Hunter (Sydney Tafler). The professor is forced to go on a mad dash to find his latest creation before it falls into the wrong hands. 'Four Days' (1951) follows Lucienne Templar (Kathleen Byron), the wife of a disgraced businessman (Hugh McDermott), as she embarks upon an affair with playboy Johnny (Peter Reynolds). But her husband soon returns from a trip to America to confront Lucienne on her infidelities.