Gleeson plays Tim, the shy son of eccentric, well-off parents (Bill Nighy and Lindsay Duncan). At 21, he leaves the family nest in Cornwall to take up his barrister pupillage in London and, yearning for love, meets Mary (Rachel McAdams), whose under-par frock and non-glam fringe can't deflect his and our appreciation of what a babe she is. Their relationship is, however, made fraught by Tim's secret superpower: he can travel back in time to any point in his own past, and correct his dopey mistakes, though creating new ones along the way. This is nearer to Sliding Doors than the dyspeptic Groundhog Day.