The shock of it. The smooth and saintly Nick Ross, presenter of BBC's Crimewatch, is a villain. And that is by his own admission.
He recently gave a talk with metropolitan police commissioner Sir John Stevens to the worthy folk of the charity Police Foundation.
But far from hearing chilling tales about those criminals lurking out there in the dark, the audience got a message somewhat closer to their cosy homes.
“The idea of dividing the world into goodies and baddies is rather naïve,” said Nick.
Then came the confession. “Who in this room has not broken a criminal law; at least fiddled on your cleaner or VAT for building work? Maybe in your social milieu, you haven't robbed a bank, but let those without sin cast the first stone.”
Backchat is sure that many in the room – especially the man in charge of the capital's constabulary – must have been quietly muttering: “Speak for yourself...”