Jonathan Creek: The Grinning Man (2009)

The set-up is told through a grainy, black and white reel film: During a balmy summer in the 1940/30's, renowned psychic and medium Jacques Futrelle holds a dinner party at his 'haunted' mansion, Metropolis. As well as his own wife and child, guests include the who's who in modern politics and media, including genetecist and scientist Eli Mencken. Futrelle tells the tale of a mysterious room, the highest room in the house, where an insane Edwardian relative confined himself. The 'Nightmare Room' is said to be haunted. Mencken, naturally, takes this on the chin and stays sceptical. Futrelle suggests he stay the night in the room, if he really doesnt believe in ghosts. Egged on by other guests, Mencken gives in, all in good humour. The windows are all locked, there are no trapdoors, just a bed, a small bathroom, and the main door. Four guests lock four padlocks on the outside, so he cannot leave without all fours co-operation. At dawn, thy unlock the door...and Mencken has vanished! Leaving nothing but a sticky ectoplasmic substance n the bed... The mystery being he has never reappeared.