Present day, England. Iris and lily Nelson, living in a large house near an army camp, are the daughters of an ex- colonel- in chief. Entertaining the camp's non commissioned officers, their latest drinking buddies are Mitch, Bobby and Danny who are preparing to leave for a tour of duty in Afghanistan.
When Mitch proposes to Iris, the sisters are apprehensive that Mitch will discover and then report to police that they have locked their brother Henry in a cell in the basement and that they have kept him there for eight years. Meanwhile, Henry having found a way to escape from his cell, stalks and savage kills a solder. this sparks off a murder hunt headed by inspector Arun.