Estate agent Norman Shenley goes into the office one morning and is met by a Mr Rayburn who wishes for him to take a look at a property. The property is called Lower Moat Manor, and the man gives him the keys and a map to get there.
When he gets there, he is greeted by a huge manor house in a terrible state of disrepair. He enters, and while standing by the dumb waiter, he hears a disembodied voice calling to him.
It goes on to tell him that he killed his wife on friday the thirteenth - today!
Suddenly, the dumb waiter descends and delivers a package - his wife! He squats over the body in surprise. When he stands up, suits of armour start to move and surround him. Then he wakes up, in bed, struggling with his wife. His wife accuses him of trying to kill her. He blames it on a nightmare. Bemused and shaken, he goes into the office early that morning.
When he gets to the office, he finds that his secretary, Lolly, with whom he is having an affair, is dressed differently - as a punk. Norman tells Lolly of the bad nightmare he had and how he found his wife dead. He speaks of Lower Moat Manor. She suggests that he tries to find the place again. Strangely, he finds that he still has the map in his pocket even though it was a dream.
Norman can find no sign of the manor, so he makes a call to Lolly from a public telephone box. While there, he looks at his map and sees the words, "Why did you do it?" Then he gets a telephone call saying, "You shouldn't have killed her Mr Shenley." Smoke starts to fill up the cubicle, and then Lolly appears from nowhere. He hears the alarm and wakes up.
He goes into work and this time Lolly is dressed as a schoolgirl. Is Norman inside yet another nightmare? Where does the nightmare end and reality begin?..
Other nightmares involve Norman visiting Lower Moat Manor again and getting duly hanged and a weird visit to a demolition site.
Norman once again wakes. He suffocates his wife to death and then goes to work, seemingly without a care. This time, Lolly is dressed conservatively and is very offhand with Norman when he attempts to kiss her. Mr Rayburn then comes into the estate agent's and introduces himself as a police detective. He asks Norman about his wife and whether she was alive when he left for work this morning. Norman, believing he is still in a dream, tells Rayburn that he killed her but that this is all a dream and he'll wake up soon. Rayburn arrests Norman, but Norman tells him that he can't have killed his wife because the 13th was days ago. Lolly tells him that today is the 13th, and Norman is taken away.