The night begins with the promise of a film premiere and exclusive director's talk, but is derailed by an unexpected sequence of events. With cunning and cool logic, crack the code to save the evening. The event starts at Millbank Tower, which overlooks the Thames, as VIP guests take their seats for the film premiere of The Image of Sarah. Suddenly the lights go off. An announcement asks the guests to remain seated and calm, then the lights return. But something's changed: the doors are all locked. Still more: lead actress Margo De'Ath appears onscreen to announce a furious message. Now the trapped guests must work together to decode 25 logic games and puzzles which will unlock the doors and set them free. Can it be done