This Harley Quin story has, if not quite everything, then nearly so: a boating catastrophe in the distant past that is neither the Titanic nor the Lusitania; a young Mr. Satterthwaite (!!) snogging (!!!!) a maid (!!!!!!); a man named Bimbo (seriously); and a true rarity for Christie—a bathtub murder. Things always get a little weird in this corner of the Christieverse (the Satterthwerse?), so fasten your seatbelts... (oh yeah--Bette Davis gets a shoutout too).
All About Agatha Christie