Thief in the Night (Persil Advert)

More soap opera than true crime, but this cinema advert is almost as cunning as its onscreen detective.

The mystery of the bogus brother burglar - a case for Sherlock Foams? Like many of the best cinema ads from this period, the puzzle for audiences was how the carefully crafted story was going to twist into a sales message. The reveal here is distinctly clever, as the clue that cracks the case highlights the USP of the product. Elementary, my dear Persil.