Detective Comics #48

In "The Secret Cavern," a startling discovery beneath Fort Knox sets off a dangerous chain of events when a man stumbles upon a hidden cavern, leading a gang of crooks to manipulate his daughter into believing she's committed murder—just to force her father to reveal the cave's secret. Written by Bill Finger and brought to life with bold, early Batman-era art by Bob Kane, with inks by Jerry Robinson and George Roussos, this 1941 thriller blends suspense and intrigue in a story that’s as much about deception as it is about the treasure beneath the nation’s vaults. The cover by Bob Kane, Jerry Robinson, and George Roussos captures the tension perfectly, a 10-cent mystery in a world where trust is the rarest commodity.