Four rookie astronauts are sent on a simulated mission to a distant planet to test the psychological effects of deep space travel. Locked away for 400 days, the crew’s mental state begins to deteriorate when things outside the module begin to go haywire and all communication with mission control is lost. Upon exiting the ship, they discover that this mission was no simulation.With their four-hundred-day mission simulation nearing completion, four astronauts begin to feel that something is amiss.