Shadow Comics #2 (1940)

The Shadow investigates a murder at the zoo involving a black leopard. A man named Ribu is found dead, and suspects include Oliver, who is hiding something, and a woman named Margo. The Shadow uses his invisibility powers to track down the real murderer—a leopard-bearing cult operating in New York—and pursues the criminals who have kidnapped a girl, attempting to rescue her before they strike again.