The Agatha Christie Hour s01e08
Titre original : The Red Signal
Dermot West is in love with Claire, the wife of his best friend, Jack Trent.
After visiting them one night he has a premonition, what he terms 'the red signal', that there is danger in the air, that death walks abroad and there is nothing that he can do about it.
When his uncle is subsequently murdered, Dermot is the chief suspect.