- "Some people are calling it the Metapocalypse, the days when Central City was overrun by an army with powers beyond imagination."
- —Iris West on the Metapocalypse[src]
The Metapocalypse was a crisis event in Central City, centered around the invasion of Zoom's meta-human group on Earth One. Said invasion resulted in massive battles of Zoom's supporters against CCPD, cases of urban destruction and the rise of meta-human crime on the streets. Ultimately, the invading meta-humans were incarcerated thanks to the joint efforts of Team Flash and CCPD.
After Caitlin Snow asked her kidnapper, Hunter Zolomon, to let her go home and take her back to Earth One, he, after initially refusing, decided to fulfill her wish in a dark way: by conquering new alternate Earths, including her home universe, stating that Earth Two has already been brought to its knees. Hunter then took hold of his beloved and left his lair together with her in a flash, presumably to gather members of his meta-human criminal organization, that supposedly was already in control of Earth Two's Central City.
Zoom and other meta-human breachers eventually traveled to Earth One, taking over the Central City Police Department. Gathering his supporters, Zoom addressed them as friends, and incited them to take control of this world from humans, as his cronies chanted in support.
A whole army of meta-humans was now trying to conquer Central City, aided with powers beyond imagination, starting massive fires and street fights. However, in the darkest hour, CCPD forces fought back, aided with special anti-meta equipment provided by S.T.A.R. Labs, although CCPD captain David Singh was heavily injured after an attack by a green fire-wielding meta-human. Team Flash also joined with his city in fighting back the Earth Two menace, with the Flash himself commenting on never before having to take on a hundred meta-humans at a time.
As CCPD started to prevail in the battle, Zoom's meta-humans spread out around the city, with Black Siren attacking whole buildings with her powers, intent on luring the Flash, and other metas going for petty street crime, such as the one attacking Wally West before being apprehended by Joe West. To neutralize Zoom's meta-human army, Team Flash devised a plan involving the Flash running around the city to create a sound barrier, while S.T.A.R. Labs utilized a sonic amplifier tuned to the frequency of Earth Two. All Earth Two breachers were rendered unconscious, except for Zoom himself, who created a breach back to Earth Two to escape the sonic attack, forcing him to change his plans and go after the Flash on his own. In the aftermath, the CCPD rounded up Zoom's meta followers and imprisoned them in Iron Heights Prison, though Black Siren was secretly imprisoned in the S.T.A.R. Labs particle accelerator. Presumably this was done as her doppelganger Black Canary had died recently, and people would ask questions they could get no answer to.