Batman! It can't be! You were killed long ago! 
World's Finest #166 is an issue of the series World's Finest (Volume 1) with a cover date of May, 1967. It was published on March 9, 1967.
Synopsis for "The Danger of the Deadly Duo!"
The criminal from the future Muto starts a series of crimes, but he is soon confonted by a notorious criminal, Joker XX, the descendant of the original Joker. Both criminals start a battle of wits until they realize they have the same goals and they decide to team up and become the most unstoppable force in crime.
Learning of Muto and Joker's crimes, Superman decides to stop them, but he is easily outmatched by their combined forces. Knowing that he'd need help to stop the criminals, Superman travels to his Fortress of Solitude to find a way to stop them using the files from his ancestors. While he was in the Fortress, Superman realizes that all of the previous heroes have been successful because they have worked with Batman as their partner. Superman is about to give up hope, when he is suddenly greeted by Batman, who is the descendant of the previous Batman, who was killed by the Joker XIX. Once again, the World's Finest team is reunited and they confront the criminals at large. While Superman fights Muto, Batman tries to capture the Joker in order to learn the whereabouts of his father. Unfortunately, Joker is killed during the fight as a lightning strikes at him and Batman never learns what happened to the Joker that killed his father.
Appearing in "The Danger of the Deadly Duo!"
Featured Characters:
- Superman XX
- Batman XX (First appearance)
Antagonists:
Other Characters:
- Superman VI (Flashback only)
- Batman VI (Flashback only)
- Superman XV (Flashback only)
- Batman XV (Flashback only)
- Batman XIX (Flashback only) (Dies)
- Joker XIX (Flashback only)
Locations:
- 2967
- Metropolis
- Daily Interplanetary News Service
- Metropolis
- Fortress of Solitude
- Batcave (Flashback only)
Items:
Synopsis for "The Genius with Super Power"
This story is reprinted from Detective Comics #227.
Look at how sad this is making Batman. You did this.
Appearing in "The Genius with Super Power"
Featured Characters:
Supporting Characters:
Antagonists:
Other Characters:
- Charley Foreman (Single appearance)
Locations:
Items:
Vehicles:
Notes
Reprinted in Superman: Past and Future.
See Also
Recommended Reading
- Superman Recommended Reading
- Action Comics (Volume 1)
- Action Comics (Volume 2)
- Adventures of Superman (Volume 1)
- Batman/Superman (Volume 1)
- Batman/Superman (Volume 2)
- Batman/Superman: World's Finest (Volume 1)
- DC Comics Presents (Volume 1)
- Superman (Volume 1)
- Superman (Volume 2)
- Superman (Volume 3)
- Superman (Volume 4)
- Superman (Volume 5)
- Superman (Volume 6)
- Superman/Batman (Volume 1)
- Superman Confidential (Volume 1)
- Superman: Son of Kal-El (Volume 1)
- Superman: The Man of Steel (Volume 1)
- Superman: The Man of Tomorrow (Volume 1)
- Superman/Wonder Woman (Volume 1)
- World's Finest (Volume 1)