Here Carr blends into his story some tricks that are the favorite plot motifs of other mystery writers. We get a story of an attempted murder in the past, a missing murder weapon from that crime, an actual murder, a faked murder and the disappearance of a tramp accidentally run down. The business with the murder weapon reminded me of Erle Stanley Gardner's obsession with switched guns and missing bullets and all the rest of the dizzying ballistics games found in his Perry Mason novels. And the final twist of where the victim was actually killed as opposed to where he was found is something that turns up quite often in the novels of Anthony Wynne. The re-enactment of the faked murder towards the end of the book, however, is pure Carr. It is simultaneously one of the most preposterous and clever bits in the books of this period when he was at his most creative. Only a reader equipped with an arcane knowledge of Canadian geology and taxidermy could possibly figure it all out.