This one shot saw the JLA teaming up with heroes from the separate WildStorm Universe.
Originally an independent company established by Jim Lee, and expanded in subsequent years by other creators, WildStorm became a publishing imprint of DC Comics in 1999. Until it was shut down, the WildStorm imprint remained editorially separate from DC Comics, with its main studio located in California. The imprint took its name from the combining of the titles of the Jim Lee comic series WildC.A.T.S. and Stormwatch.