Vernon Gray is the oldest and richest of the residents of the four flats on the sixth floor of a block in his small seaside town. After seeing her on TV, he has instructed Rosa Epton to draft his last will and testament, when another of her clients demands her attention on an urgent matter: he has been accused of stealing five pounds from the collection plate at the end of the Sunday morning service.

And then Vernon Gray disappears, along with his housekeeper, leaving a welter of puzzling clues to confuse the police, and the learned Rosa.