Comic Title: Action Comics #18
Publisher: DC (Detective Comics, Inc.)
Address: 480 Lexington Avenue, New York, NY
Cover Date: November 1939
Approx. On Sale Date: September 28, 1939 Copyright Date September 25, 1939
Source: Library of Congress, Periodicals 1939
Until 1958 DC did not report actual on sale dates to the copyright office
The publication dates listed in LoC records are NOT release dates.

Frequency: Monthly
Cover Price: $0.10
Page Count: 64
Editor: Vincent A. Sullivan

Title: "The Atlantis Mystery"
Pages: 11

Feature(s):
Zatara (of Earth-2)

Writer: Gardner F. Fox
Artist: Fred B. Guardineer

Feature Character(s)

• Zatara (last appearance in Action Comics #17; next appearance in Action Comics #19)

Villain(s)

• Barnacle Will and his men (sailors; no further appearances)
• Several underground creatures (no further appearances)
• Roor (a giant octopus; no further appearances)

Other Character(s)

• Setap (last appearance in Action Comics #17; no further appearances)
• Gath and Loalla (no further appearances)

Synopsis:
Setap, the former Queen of Ophir, approaches Zatara for help in discovering the lost city of Atlantis. Zatara agrees to join the search which leads them to an underwater cavern. Barnacle Will, one of the sailors accompanying them, is only interested in gold and betrays the adventurers. However, Zatara's magic overcomes him.

Zatara and Setap then discover the entrance to Atlantis. They meet Gath, an Atlantean elder who teaches them the history of Atlantis. Barnacle Will, however, tries to steal gold from the city. His actions unleash Roor, a giant octopus. Zatara's magic is ineffective against the monster, but he prevails anyway.

Setap decides to stay behind in Atlantis, while Zatara bids the Atlanteans farewell.