Sir John Appleby and his wife, Lady Judith accept an invitation to a house-party at Charne, the country estate of the Martineaus. Their friend, Grace Martineau is dying of cancer and she wants her friends about her one last time.
Innes paints believable psychological portraits of his protagonists. The deaths don't take place until the latter half of the mystery. Meanwhile the reader becomes well-acquainted with Grace Martineau and her machinations to have her husband remarry after she has died.
Her guests, already on edge because they know this is the last time they will see their hostess, are shocked by her insistence that her husband should wed another after her passing. They are even more shocked when they learn Grace's choice of bride.
It's a good mystery, where the reader is challenged to discover a killer, after the author has furnished revealing psychological portraits of the murder suspects.