The cover of Detective 52 (June 1941) does reflect the story inside, a “yellow peril”tale about a jade box.
The centre of the tale is a ring that supposedly belonged to Genghis Khan. Possession of the ring entitles one to control all the gangs.
As with the earlier Chinatown tale, Batman orders Robin to stay behind, that it is too dangerous, but he tags along anyway and saves Batman’s life.
Kay has been around a while, a sort of platonic girlfriend. In this issue, we learn her last name, Nevers. She and Cliff must be having some degree of serious relationship, because they stay at a hotel together.
The only Steve Malone story towards the end of the run that really sticks out for me is this one, in which a yacht crashes onto Long Island Sound with a man hanging from the rafters inside. The man is never shown, but his shadow is seen, cast on the wall, and we see the facial reactions of the people looking at him.
Aside from that, it’s a pretty standard tale, ending with an entire page of explanations, so I’m not even going to try to summarize. The explanation takes up 1/6 of the story’s length