Indeed, he is Harlequin. The only consistent thing about the Mysterious Mr Quin is that his presence is always a harbinger of love ... or death.
Quin and Satterthwaite appear in a string of short stories by the incomparable Agatha Christie. She often said that some of them are among her personal favourites. They'll be yours too.
The stories are: 1 The Coming of Mr. Quin; 2 The Shadow on the Glass; 3 At the "Bells and Motley", 4 The Sign in the Sky; 5 The Soul of the Croupier; 6 The Man from the Sea; 7 The Voice in the Dark; 8 The Face of Helen; 9 The Dead Harlequin; 10 The Bird with the Broken Wing; 11 The World's End; and, 12 Harlequin's Lane.
Librarian's note #1: besides those in this collection, there are two more Mr. Quin stories found in other collections: 'The Love Detectives', and 'The Harlequin Tea Set'.
Librarian's note #2: this is the entry for the collection of 12 short stories, "The Mysterious Mr. Quin'. Entries for each of them are located elsewhere on Goodreads. All 14 stories can be found by searching Goodreads for: 'a Harley Quin Short Story'.
The Mysterious Mr. Quin - Agatha Christie
The Mysterious Mr. Quin by Agatha Christie..Harley Quin is an enigma. Even his friend Mr Satterthwaite is unable to understand how the man seems to appear and disappear almost like a trick of the light - and when he does appear it's usually in the sparkle of sunshine, or surrounded by a spectrum of coloured light pouring through a stained glass window.