Detective Comics #650 1992

In Detective Comics #650, Harold and Ace the Bat-Hound uncover hidden passages within the Batcave, revealing its connection to the Gotham subway system. Meanwhile, Robin races against time to thwart a decades-old murder plot, saving a news crew from a booby-trapped vault during a live broadcast. This issue is notable as Batman only appears on the cover, with the story focusing on Robin and Harold, marking Harold's first appearance in Detective Comics. It features writing by Chuck Dixon.