Let Sleeping Corpses Lie (, Do Not Profane the Sleep of the Dead; , Do Not Profane the Sleep of the Dead), also known as The Living Dead at Manchester Morgue and Don't Open the Window, is a 1974 Spanish-Italian science fiction zombie horror film written and directed by Jorge Grau and starring Ray Lovelock, Arthur Kennedy and Cristina Galbó. It focuses on two protagonists who are harassed by a local police investigator in the English countryside and are implicated in murders committed by zombies who have been brought to life by a farming tool designed to kill insects via ultra-sonic radiation.
After being presented at the Sitges Film festival in Spain on 30 September 1974, the film was released in Italy on 28 November 1974 and was later released throughout 1975 in the United States and the United Kingdom under varying titles. In total, the film was released under more than 15 different titles internationally. In the following years, the film has become a cult picture.
Plot
George is taking a trip from an antique shop in Manchester to the Lake District. On the way, his Norton motorcycle is accidentally damaged by Edna while reversing her Mini Cooper at a petrol station. He demands she give him a lift to his destination, while Edna, on her way to visit her troubled sister, asks to go to the town of Southgate first, and to let George take her car to Windermere where she will later retrieve it.
George agrees, but the two come to a dead end road alongside a river while searching for Edna's sister's house. George crosses the river on foot to a farm where several men from the Ministry of Agriculture are using an experimental machine in a field. While asking for directions, he inquires about their machinery, which they explain is designed to kill insects through ultra-sonic radiation. Meanwhile, while Edna waits at the car, she is attacked by a man who emerges from the river. She runs to find George for help, but her attacker is gone when they return to the car.
Night falls and the film shifts focus: Edna's sister, Katie, is shown awaiting Edna's arrival, and is revealed to be addicted to heroin. Katie gets into an argument with her photographer husband, Martin, about her sister's impending arrival. Martin goes down to a waterfall near their remote cottage to complete a night-shoot of some plant specimens. Meanwhile, Katie, while preparing to take heroin, is attacked by the same man who Edna had encountered earlier. Katie is pursued to Martin's photo-shoot, where the man kills Martin, and Katie flees just as George and Edna arrive. When the three report the death, the aggressive police sergeant suspects foul-play from the trio. George, forced to stay in Southgate as a person-of-interest to the investigation, secretly takes the roll of film from Martin's camera to a local chemist to have it developed. Katie has a breakdown and is hospitalised. Visiting the hospital, babies are acting strangely, biting and scratching people with homicidal intensity.
Back at the chemist's, George and Edna collect the photos, but the dead man does not appear in any of the pictures; the man, it turns out, is a local vagrant who drowned in the river. The sergeant arrives and confiscates the photos and, when the couple leaves, sends one of his officers, PC Craig, to follow them. They go to the graveyard and in a room in the chapel find a half-eaten meal. Following noises to a crypt, they come across the vagrant's casket empty, along with a murdered man. Locked into the crypt by an unseen figure, they again encounter the zombified vagrant, who brings the other bodies to life by touching their eyes with his blood-stained fingers. The pair manage to make their escape along a ladder, kicking out a hole to climb into a freshly-dug grave. PC Craig arrives and helps Edna out of the pit. George follows and the trio are then pursued by the zombies into the church itself. They lock themselves in a room but are trapped there, with PC Craig finding his gun is of no use against the zombies. He makes a dash for the police radio he has dropped outside but is caught by the zombies who kill and devour him.
The dead break into their room and in desperation George throws a lit oil lamp at them. It smashes and the zombies burst into flame. The two escape to their car and Edna is sent off to tell the police. George heads to the experimental agricultural machine, where the farmer and two government men do not believe George, and reveal that the machine is now working with a newly effective five-mile radius. They try to stop him, but he smashes the machine.