Finland - Winter 1885. Retired school teacher, Efraim Martin, lives in the village of Ylöjärvi with his wife Eva and their young maid, Emma. A secret pact with the Devil sends the unsuspecting family's life on a sudden detour into fear. Unseen forces wreak havoc in the cottage, throwing dishes, burning documents and attacking the unsuspecting. People end up witnessing dozens of frightening supernatural events before their very eyes.
Thus begin the 16 days of haunting known in the annals of parapsychology as "The Martins and the Devil." Crowds of curious onlookers gather to watch the strange spectacle. Some of the villagers believe in these supernatural phenomena, and others don't. The Martins are taken to court and accused of witchcraft. When matters could not get any worse Emma falls fatally ill and the house becomes dangerous to all its inhabitants. Then a mysterious Lapp Witch appears to intervene. A dark secret is revealed - but time is running out. Efraim must save Emma before her soul is lost forever.