Psychological horror directed by Ben Wheatley. Set during the English Civil War, the film follows a small group of deserted soldiers who are captured by a mysterious alchemist by the name of O'Neil (Michael Smiley). When they are forced to help O'Neil find treasure that is believed to be hidden in a field, they feed themselves on the abundant mushrooms found in the English countryside. As their search continues, the group begin a quick descent into paranoid psychological turmoil and begin to suspect that the treasure they have been seeking may be something else altogether.