As background for its multi-part epic Crisis on Infinite Earths, DC Comics released Crisis on Multiple Earths to introduce (or refresh) the reader to the concept of multiple Earths coexisting in the same physical space by vibrating in different dimensions. This volume collects four different story lines (each encompassing two issues) involving the Earth-One Justice League of America (the most familiar DC stars such as Superman, Batman, and Wonder Woman) and the Earth-Two Justice Society of America (older heroes, some with Earth-One counterparts such as the Flash and Green Lantern, but some unique heroes such as Doctor Fate and Hourman), all from the mid-'60s and written by Gardner Fox with pencils by Mike Sekowsky. The best story introduces Earth-Three, where only criminals have the super powers. Bored with committing easy crimes, the Crime Syndicate of America--a band of supervillains with knockoff costumes and dumb names ("Power Ring," "Johnny Quick")--challenges the JLA and JSA to battle. The other stories involve the Crime Champions of Earth-One and -Two, Johnny Thunder's Thunderbolt, and Solomon Grundy and Blockbuster. For more crossover action, Crisis on Multiple Earths was followed by a volume 2. Alex Ross did the cover paintings for all three Crisis... books.--David Horiuchi