Dodgy Decepticons and chummy Autobots go head-to-head. Again. The third instalment of director Michael Bay's metal monster mash-up features his greatest conceit yet - imagining a scenario where American astronauts Neil Armstrong and Buzz Aldrin discover a crash-landed Transformer on the moon. This time round the villainous Shockwave takes the stage and traitors lurk in some very unexpected places. Shia LaBeouf returns as human hero Sam Witwicky, though Megan Fox makes way for British vixen Rosie Huntington-Whiteley in his affections.