Of all the criminal cases in which Philo Vance participated as an unofficial investigator, the most sinister, the most bizarre, the seemingly most incomprehensible, and certainly the most terrifying, was the one that followed the famous Greene murders. The orgy of horror at the old Green mansion had been brought to its astounding close in December; and after the Christmas holidays Vance had gone to Switzerland for the winter sports. Returning to New York at the end of February he had thrown himself into some literary work he had long had in mind-the uniform translation of the principal fragments of Menander found in the Egyptian papyri during the early years of the present century; and for over a month he had devoted himself sedulously to this thankless task.