Deliria tells the story of Sammy Jacobs, a young woman who is having trouble coping with her growing depression. Determined to save Sammy from herself, six of Sammy's closest friends decide to take her on a whirlwind trip up north and stay the weekend on the island of Deliria. Once on the island, Sammy and her friends become captivated by the local lore of the isle's surrounding woods, and the ominous power it possesses. Seeing herself as having nothing left to lose, Sammy proceeds to tempt fate and enter the woods; the result of which is the restoration of her mental state. However, this experience is not shared by everyone in the group. In fact, for the rest, the inverse is true: as Sammy slowly starts to regain her sanity, each of her friends begins to lose theirs.