Batman Legends of the Dark Knight #181 (1989)

Written by Dylan Horrocks; art by Ramon Bachs and John Holdridge; cover by Tom Fowler
In stores July 14. An investigation into the death of a computer hacker has led Oracle to a secret cyber-world hidden in the bowels of Gotham. But now more bodies are turning up, and someone who might just be the Joker has turned his attention to Oracle!