Andrew Alburn, a homeless veteran suffering from PTSD, is plagued by flashbacks of a traumatic event he witnessed while serving in the armed forces. He retreats to the remote Scottish Highlands hoping to overcome his fear of Ravens, the dark creatures that populate his visions, but, in this bleak wilderness, his nightmares manifest into an enemy more powerful than he could ever have imagined. He must battle these monstrous entities as well as his inner demons to keep his life, and reclaim his sanity.