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 from 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. With theories of levitating vampires abounding, the story comes home to Miles when he realises that the librarian he has just hired for his home is none other than Fay Seton, a woman whose name still echoes from the heart of this bizarre and unsolved murder of the past.

First published in 1946, in later years Carr considered this novel one of his finest works. It shows the masterful author at the height of his powers, boasting an ingenious plot delivered with an astounding pace and striking characters including none other than the great detective, Dr Gideon Fell.