Brainiac collects cities and inhabitants from various timelines that have ended and traps them in domes on a planet outside of time and space.  He then exposes the domes to one another to see how the characters interact.  This event marks the return of DC characters and timelines from before the 2011 "Flashpoint" storyline and is the end of The New 52 branding.

Collects Issues #0-8.