Nigel Strangeways is off to a Christmas houseparty hosted by Fergus O’Brien, a legendary World War I flying ace now retired from private life, who has received a series of mocking letters predicting that he will be murdered on Boxing Day.
His guest list includes everyone who could even remotely be suspected of making the threats, including several people who stand to profit from O’Brien’s death, as well as Nigel, who is invited in his capacity as a criminal investigator.
Despite Nigel’s presence, the murder takes place as predicted, and he’s left to aid the local police in interviewing the suspects. One of them is Georgia Cavendish, a brave and colorful explorer who has been romantically linked with O’Brien and with whom Nigel falls in love.
Convinced that the case will never be solved unless the mystery of O’Brien’s past is cleared up, Nigel heads for Ireland to learn what he can about the victim’s origins. Originally published in 1936, it’s the second mystery by Blake (really C. Day-Lewis, the late Poet Laureate of England) and without a doubt one of his best, with its dazzlingly complex plot, arresting characters, and shocking but inevitable solution.