Cosh in the Attic.
Interactive whodunnit plus antiques, thereby capturing key daytime demographic.
Alistair Appleton and other regular presenters are taken into a punter’s house under the misapprehension that they are attempting to find valuable antiques among the tat typically found in houses in this sort of programme (Car Booty, &c you know the sort of thing). A bit of antiques chat for half the programme. Then, having been encouraged to go into the attic on a search for family heirlooms the presenter is hit over the head with a truncheon or other blunt instrument. Viewers then encouraged to find the attacker from hints within the programme. Viewers guesses to be made using premium rate telephone lines. Correct answer in following programme. Winner drawn from lottery and gets prize of some tat from punter’s house.