This is one of Josephine Tey's lesser known mysteries. "Daughter of Time" and "The Franchise Affiar" are, perhaps better known. This novel is in the Inspector Grant series and concerns the disappearance of a young man whom Grant had met briefly at a party.
The writing and atmosphere of this novel are both excellent. Unlike some other Tey novels, I enjoyed this one more for the characters and setting, rather than plotting. Tey has a fine ear for dialogue and humor and Grant is a pleasure to go detecting with.