Comic Title: World's Finest Comics #155
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: February 1966
On Sale Date: December 9, 1965 Copyright Date December 9, 1965
Source: Library of Congress, Periodicals 1965

Frequency: Monthly, with the exception of Jan., April and July
Cover Price: $0.12
Page Count: 32
Editor: Mort Weisinger

Title: "Exit Batman -- Enter Nightman"
Pages: 18

Feature(s):
Superman (of Earth-1)
Batman (of Earth-1)

Writer: Edmond Hamilton
Penciller: Curt Swan
Inker: George Klein

Reprinted In:
Showcase Presents:World's Finest Vol. 3 TPB (2010)
Batman & Superman in World's Finest Comics:The Silver Age Omnibus Vol. 2 HC (2019)

Feature Character(s)

• Superman (last appearance in Superman's Girl Friend, Lois Lane #64; next appearance in Justice League of America #43)
• Batman (last appearance in Superman #186; next appearance in Brave and the Bold #64)

Supporting Character(s)

• Robin (last appearance in Superman's Pal, Jimmy Olsen #91; next appearance in Detective Comics #348)
• Commissioner Gordon (last appearance in Batman #178; next appearance in Brave and the Bold #64)
• Jimmy Olsen (last appearance in Superman's Girl Friend, Lois Lane #63; next appearance in World's Finest Comics #156)
• Perry White (last appearance in Superman's Girl Friend, Lois Lane #64; next appearance in Superman #185)

Villain(s)

• Several criminal gangs (no further appearances)

Other Character(s)

• Ace Lanner, Emilio Ruyez, and Jay Lonn (an insurance investigator, a Mexican lawman, and a secret agent; no further appearances)
• A Batman robot (disguised as Nightman; no further appearances)
• A group of international lawmen (no further appearances)

Cameo Appearance(s)

• Joker (as a trophy in the Batcave)

Comments:
Part 1: "The 1,000th Exploit of Superman and Batman"
Part 2: "The Incredible Identity of Nightman"

Perry White is shown as the editor of the Daily Planet in this story, so it must take place chronologically following the second story of Superman's Girl Friend Lois Lane #64, in which Perry finished his term as a temporary senator.

Synopsis:
The Daily Planet and a group of international lawmen plan a celebration commemorating the one-thousandth case involving Superman and Batman. At the ceremony Batman claims that he is undeserving of the honor, since Superman has recently worked with a crime-fighter named Nightman, whom Batman feels is superior.

In an attempt to prove himself, Batman seeks to learn Nightman's identity, vowing to let the new hero replace him if he fails. Batman pieces together clues and narrows his search to three suspects. While each proves to be a false lead, Nightman helps Superman again.

At another meeting of the international lawmen, Batman announces that he has solved the riddle. Nightman appears and defeats Batman. Superman then announces that this Nightman is a phony and is really a Batman robot. Batman had deduced that he himself was Nightman and had substituted the robot as a prank. Superman then explains that he hypnotized Batman, making him take on the Nightman persona. The prank was done in order to give Batman a mystery to solve as part of the anniversary celebration.