Mr. Satterthwaite bumps into his old friend Mr. Quin at the opera at London’s Covent Garden. During intermission, they spot a strikingly beautiful but distressed young woman in the audience. Later, they discover that she may be in real danger and decide to rescue her. Librarian’s note #1: this short story was published in ‘Story-Teller’ (1927) 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: ‘a Harley Quin short story.’ Details such as characters and settings are included for each.