March is invited to a nightclub by Arthur Cabot to see Francine Rapport perform a Javenese dance. March is a fan and somewhat of an expert in Javanese dance. During the performance, March sees in the dance moves what he believes to be a cry for help. Soon thereafter, Rapport is found dead in her dressing room. It seems she had been blackmailing a man over some letters he had written to her. When the man's girlfriend is caught trying to flee the dressing room, she immediately becomes the prime suspect. March goes to the British Museum to do some research on dance and his exchange with the librarian while there is the best part of the episode (perhaps because I'm a retired librarian). While reading, March suddenly laughs loudly (and what a great laugh Karloff had) and the librarian comes up to him and says "You shouldn't laugh in here." He asks "Why not, isn't it allowed?" Says she: "Oh, it's allowed, it's just never done." Soon later someone throws a knife at March but it lands into a book he's holding. As he's leaving holding the book with the knife sticking out of it, the librarian approaches him and showing no concern about how the knife really got into the book says "Books should not be mutilated. You're a very naughty boy." "I'm not the only one" says March. Sure, overly stereotypical of librarians, but funny. There are so few suspects that's it's not hard to figure out who the culprit is, but nonetheless a highly enjoyable episode. Richard Wattis as Cabot was easy to recognize; I think of him mostly in comic roles as an officious character. On the other hand, Dana Wynter wore such heavy make-up, I only know she was in the episode because of the IMDb credits.