It's Saturday night at the movies as Strictly celebrates some of the biggest films in history. We are now down to 14 couples and every one of them has to deliver an amazing routine to a classic movie track to stay in the competition. Plus, we have a surprise judge - for one night only, pop legend Donny Osmond will be joining the panel. Donny is a winner of Strictly in the US, so who better to analyse our celebrities' moves and give them words of wisdom? Tess Daly and Claudia Winkleman host an evening full of sparkling moves, iconic songs and plenty of surprises.