On the surface, the film is a globe-trotting gross-out caper in which Nobby, who's from a hellish version of the titular Lincolnshire town ("twinned with Chernobyl"), is reunited with his long-lost brother Sebastian (Mark Strong), who has become a spy for the British secret services. That makes him a servant of the powers-that-be that have no time for Nobby and his scrounging ilk.