Communing with Mr. Quin: The Love Detectives by Agatha Christie

The love detectives are back--and in a story titled The Love
Detectives, no less! Join us as we puzzle over why this perfectly
delightful serialization was the only one not to be included in the
Mysterious Mr. Quin collection… and potentially figure it out in
real time! (Clearly the magic of Mr. Quin, that wily catalyst of
problem-solving, was with us.)