“The Roman Hat Mystery” is based on records actually to be found in the police archives of New York City. Ellery and his father, as usual, worked hand-in-hand on the case. During this period in his career Ellery was a detective-story writer of no mean reputation. Adhering to the aphorism that truth is often stranger than fiction, it was his custom to make notes of interesting investigations for possible use in his murder tales. The affair of the Hat so fascinated him that he kept unusually exhaustive notes, at his leisure coordinating the whole into fiction form, intending to publish it. Immediately after, however, he was plunged into another investigation which left him scant opportunity for business; and when this last case was successfully closed, Ellery’s father, the Inspector, consummated a lifelong ambition by retiring and moving to Italy, bag and baggage. Ellery, who had in this affair[1] found the lady of his heart, was animated by a painful desire to do something “big” in letters; Italy sounded idyllic to him; he married with his father’s blessing and the three of them, accompanied by Djuna, went off to their new European home. The manuscript was utterly forgotten until I rescued it. [1] “The Mimic Murders.” This crime in its fiction form has not yet reached the public. J. J. McC. On one point, before I close this painfully unhandsome preface, I should like to make myself clear. I have always found it extremely difficult to explain to strangers the peculiar affinity which bound Richard to Ellery Queen, as I must call them. For one thing, they are persons of by no means uncomplicated natures. Richard Queen, sprucely middle-aged after thirty-two years’ service in the city police, earned his Inspector’s chevrons not so much through diligence as by an extraordinary grasp of the technique of criminal investigation. It was said, for example, at the time of his brilliant detectival efforts during the now-ancient Barnaby-Ross murder-case,[2] that “Richard Queen by this feat firmly establishes his fame beside such masters of crime-detection as Tamaka Hiero, Brillon the Frenchman, Kris Oliver, Renaud, and James Redix the Younger.”[3] [2] Ellery Queen made his bow as his father’s unofficial counsel during this investigation. [3] Chicago Press, January 16, 191-. Queen, with his habitual shyness toward newspaper eulogy, was the first to scoff at this extravagant statement; although Ellery maintains that for many years the old man secretly preserved a clipping of the story. However that may be—and I like to think of Richard Queen in terms of human personality, despite the efforts of imaginative journalists to make a legend of him—I cannot emphasize too strongly the fact that he was heavily dependent upon his son’s wit for success in many of his professional achievements.