Jonathan Creek: Ghost's Forge (1999)

An old friend of Maddy's wants her and Jonathan to investigate a house called Ghosts Forge, as she is having an affair with a man who keeps muttering about it in his sleep. Investigations reveal that the last owner of the house was found dead several years ago and the place is now being rebuilt into flats. As Jonathan looks into the man's real identity — his only clue being a package in the attic containing six books by a best-selling author — Maddy takes the opportunity to perform a disappearing trick of her own.