Marshall O'Neil (Connery) knows about living life in limbo — his wife left him and had taken their son along with her, and he's stranded in a forgotten mining town on one of Jupiter’s moons. But there's more to worry about when the miners start killing themselves in bizarre ways. His investigations into their deaths lead him to discover that their mine boss, Sheppard (Boyle), has been keeping his workers on overtime by feeding them a work-enhancing drug with deadly side-effects.