Season 4 begins with a mind-bending jump in time
Murphy and Warren find themselves alive in Zona, the zombie free playground for billionaires

Meanwhile, the rest of our heroes are fighting alongside the last of the humans against the mutated Zombie Virus and the unkillable "MAD-Z's."
Warren's mysterious dream of a black rainbow and flesh-eating black rain propels the season forward

And puts our heroes in the middle of an even worse Zompocalypse
Here they will have to battle Jugalo Zombies and find the Zombified President of the United States -- or at least his thumb