Their imaginations spurned on by reports of a serial killer on the loose, a pair of nurses care for an invalid patient at a remote country home and begin to suspect that they might become the next victims following a series of strange occurrences. Wairarapa, New Zealand: 1932. The groundskeeper at an isolated estate leaves Louise and Martha with their patient and the housekeeper as he drives into town to find a new oxygen cylinder for the ailing woman. Frightened by a rash of recent murders in which young nurses were found strangled to death, Louise and Martha lock the home up tight and prepare to wait for the groundskeeper to return the following morning. As night falls, the housekeeper becomes incapacitated, various items around the house are inexplicably moved, and strange sounds echo out from the darkness. As Louise and Martha brace themselves for the worst, they begin to wonder if their overactive imaginations have finally gotten the best of them.