Fleeing from a battle in the English Civil War, a small group of deserters are captured by a mysterious alchemist and forced to aid him in his search for treasure he believes is buried in a nearby field. Crossing a vast mushroom circle, which provides their first meal, the group quickly descends into a chaos of arguments, fighting and paranoia; and, as it becomes clear that the treasure may be something other than gold, they slowly become victim to the terrifying energies trapped inside the field. A psychedelic trip into magic and madness from the director of "Kill List" and "Sightseers".