When Miles Hammond is invited to a meeting of the Murder Club in London, he is met instead with just two other guests and is treated to a strange tale of an impossible crime in France years before; the murder of a man on a tower with only one staircase, under watch at the time at which the murder took place. The story comes home to Miles when he realises that the librarian he has just hired is none other than Fay Seton, a woman at the heart of this unsolved past murder. From one of the highest-rated authors of the genre.