Everyone tries to escape the impending nuclear blast; Citizen Z battles thawed zombies and issues an air bounty for Murphy.
The heroes are reunited, but soon find themselves navigating an unexpected tragedy as they engage in fierce fighting with both zombies and bounty hunters who are eager to capture Murphy, dead or alive. Meanwhile, Vasquez makes a strategic decision.
Murphy is finally tracked down; the Zs are attacked by superfast zombies known as Blasters; and they are introduced to an ultrapotent strain of marijuana called Z-Weed.
The survivors search for a "natural" cure for the virus at a greenhouse that's being guarded by zombie-plant hybrids.
A pregnant Serena tracks down Murphy; the survivors stumble across a hidden Mennonite farm with new dangers.
While Murphy is falling for his baby girl, the rest of the team is suspicious of her; Vasquez sneaks away for a meeting; 10K makes a difficult decision.
While crossing the Mississippi, the team splits up after a boating accident; 10K is drawn into a scam; Escorpion sentences 10K, Sketchy and Skeezy to death.
Murphy is captured by an unbalanced zombie fan, who is eager to add him to a zombie museum, so he must match wits to escape.
The team finds an abandoned Air Force base and discovers what looks like alien technology.
The team splits up because of a massive zombie horde, and encounters a Native American tribe fighting against itself.
The team gets embroiled in corporate politics after finding a group of white collar survivors hiding out in a hotel.
The team meets La Reina, Queen of the Zeros, after being captured; Dr. Kurian is ready for human trials on his Z-vaccine at the Zero compound.
It's discovered that the Z-vaccine doesn't work; Vasquez gets caught trying to hug Escorpion; Murphy uses mental manipulation to help Roberta.
The team reaches California and thinks back to the beginning of the zombie apocalypse.
The team reaches the mobile lab, which turns out to be a submarine; Murphy says goodbye.