With its most recent Secret Wars event, Marvel destroyed most of its parallel universes where some of the most interesting stories were set. These "elseworlds" stories (those that take place outside of a publisher's regular canon) reimagined classic characters such as the X-Men and the Avengers as versions of themselves that were nothing like anything we'd ever seen before.

Though it isn't difficult to understand why Marvel wanted to simplify its multiverse as it headed into its latest publishing reorganisation, in doing so, it closed the door on a number of engrossing stories that explored what a true science fiction multiverse could be.