Crisis on Multiple Earths #4

This fourth volume in the Crisis on Multiple Earths trade paperback series collects Silver Age crossovers featuring the Justice League of America and the Justice Society of America, alongside the original Captain Marvel family and the Legion of Super-Heroes. Stories from the 1970s bring together Earth-1 and Earth-2 heroes like Batman, Superman, and Robin with their Golden Age counterparts, while also incorporating characters such as Billy Batson, Bulletman, and the Legion's Brainiac 5 and Saturn Girl in multiverse-spanning adventures. The collection highlights DC's interconnected Earths before the continuity-altering events of Crisis on Infinite Earths, showcasing team-ups that were foundational to the publisher's multiverse concept.