Dagger of the Mind

Lilian Stanhope and Nicholas Frame are two actors in London. They have to act in Macbeth and the producer is Sir Roger Haversham who is Lilian's lover. Sir Roger finds out he has been deceived by the couple and he threatens to interrupt the performance. Lilian kills him accidentally during a fight and afterwards the two actors take the corpse to his mansion, staging an accident. But Lt. Columbo is in London to learn about the new methods to investigate used by Scotland Yard. (imdb)