The novel, and the other "nationality" mysteries, had the unusual feature of a "Challenge to the Reader" just before the ending is revealed—the novel breaks the fourth wall and speaks directly to the reader. "It has been my custom to challenge the reader's wits at such point in my novels at which the reader is in possession of all facts necessary to a correct solution of the crime or crimes. "The Egyptian Cross Mystery" is no exception: by the exercise of strict logic and deductions from given data, you should now be able, not merely to guess, but to prove the identity of the culprit."