Twilight Zone Second Season

"The prostrate form of Mr. David Ellington, scholar, seeker of truth and, regrettably, finder of truth. A man who will shortly arise from his exhaustion to confront a problem that has tormented mankind since the beginning of time. A man who knocked on a door seeking sanctuary and found instead the outer edges of the Twilight Zone."

David Ellington is on a walking trip of Europe following WWI when he gets caught in a storm. He finds a remote hermitage, but is turned away. After he passes out, the monks are forced to take him in. After reviving, he hears a howling that the brothers say they do not hear. Following the sound, he comes upon a cell with an old man locked inside. The old man says he is being held captive by Brother Jerome, who is insane. After confronting Brother Jerome, he confesses that he is holding the old man prisoner, but the old man is actually the Devil! Ellington promises to keep this secret, but as soon as he gets a chance, he returns to the cell and releases the old man - who proceeds to transform into the devil and disappears. Shortly after, WWII breaks out. Ellington devotes his life to recapturing the Devil. He finally does recapture the Devil. As he prepares to leave to make arrangements to ship him back to the hermitage, he tells his housekeeper to pay no mind to the howling. But, as soon as he leaves, she lifts the bar on the door, and the door swings open.

"Ancient folk saying: 'You can catch the Devil, but you can't hold him long.' Ask Brother Jerome. Ask David Ellington. They know, and they'll go on knowing to the end of their days and beyond - in the Twilight Zone."