It’s dark and cold, with snow drifts everywhere, when Mr. Harley Quin appears at the door of Royston Hall stating that his car has broken down. Once inside, he finds a small party celebrating the new year. Quin remarks that he knew the previous owner of Royston Hall. He then launches into the tragic tale of the former occupants leading to a dramatic change in the perceptions of the current inhabitants. But has Mr. Quin’s revelation come too late? Librarian’s note #1: ‘The Coming of Mr. Quin’ was first published as ‘The Passing of Mr. Quinn,’ that’s with two n’s, in Grand Magazine (March 1923) and then in the print anthology ‘The Mysterious Mr. Quin’ which was first published in 1930. Librarian’s note #2: the print anthology contains 12 Mr. Quin short stories. Besides those, there are two more found in other collections: ‘The Love Detectives,’ and ‘The Harlequin Tea Set.’ Mr. Satterthwaite also appears in ‘Three Act Tragedy’ and ‘Dead Man’s Mirror.’ All by Agatha Christie, of course! Librarian’s note #3: the entries for all fourteen Mr. Quin short stories can be found on GR by searching for: ‘a Harley Quin short story.’ Details such as characters and settings are included for each.