Thirty-something, out of work, separated from his wife and alienated from his autistic son, Barney retreats into the fantasy world of his past. He harks back to the do-or-dare days with his mates, Winkie, Pompus, Stubbs and Tony Football. Nearly twenty years later, rummaging in the attic, Barney unearths a priceless possession, one that reunites his old circle of friends. As the men get involved in the re-creation of their childhood game--this time with very grown-up stakes--jealousies, rivalries and enmities test their friendship to breaking-point and even threaten their lives. Now, everyone is willing to do or die for the little green man...except this time it's for keeps.