Batman Legends of the Dark Knight (1989) #67
Going Sane, Part 3 of 4. Recovering from a nearly lethal attack by his archnemesis, Batman resumes his search for the Joker. But the trail leads the Dark Knight unexpectedly to Joseph Kerr, a contented, well-adjusted man who seems too utterly sane to be the maniac Batman seeks.
Written by J.M. DeMatteis, with art and cover by Joe Staton and Steve Mitchell. Deluxe format.
Cover price $1.95.