Robbie's wedding is halted by the presence of a sinister crystal and his fiance, Donner, is kidnapped by aliens. Robbie must embark on a mission to stop the destruction of the planet by the evil Vorkana, Queen of the Nargathrons. But with the clock ticking and a best man too love sick to be of any assistance, will our hero rescue his sweetheart and save the world in time? New to the cast in the third film of the series are Keira Knightley, Ozzy Osbourne, Gillian Anderson, Russell Brand, Graham Norton, Ross Kemp, Shane Richie and Michael Palin. They'll join a returning cast of Ardal O'Hanlon, Jane Horrocks, Harry Enfield, Paul Whitehouse and Sean Hughes.