In "The Observer" of 18 December 1938, "Torquemada" (Edward Powys Mathers) finished his review by stating defensively, "'Is Hercule Poirot's Christmas' a major Christie? I think it is, and that in spite of a piece of quite irrelevant tortuosity in the matter of the bewitching Pilar Estravados, and in spite of the fact that the business of the appalling shriek will probably make no mystery for the average reader. The main thing, is, surely that Agatha Christie once more abandonedly dangles the murderer before our eyes and successfully defies us to see him. I am sure that some purists will reverse my decision on the ground that the author to get her effect, has broken what they consider to be one of the major rules of detective writing; but I hold that in a Poirot tale it should be a case of caveat lector, and that the rules were not made for Agatha Christie."