10 Times Batman And The Joker Saved Each Other
3. The Joker Turns Detective - Fool's Errand
A typically dark and 'gritty' piece of '90s comic book writing, Detective Comics #726 sees our masked vigilante's detective skills come up short when hunting for a kidnapped little girl. As a result, he has to turn to a certain someone for help. Batman discovers that the man who had done the kidnapping was in fact in the cell next to Joker when they were imprisoned together in Arkham.
The Joker, of course, was expecting the interrogation that ensued and has some fun at the Caped Crusader's expense. Our vigilante deduces that his old enemy had in fact planned the kidnap of the little girl, due to it being done on the anniversary of the death of Jason Todd; something only the Joker would know. Unexpectedly, however, Mr. J then presents Bats with the exact location of the girl, allowing him to save her from a hostage situation in the nick of time.
Confused as to why the Joker would do this, it seems the Clown Prince of Crime enjoys the idea that he has given Batman hope, both with regards to saving hostages from dire situations, as well as perhaps more generally.