As the Woodbury survivors join Rick's group, the survivors are treated to a period of peace in the prison, but the peace is shattered with the arrival of a new survivor.
As the group deals with the aftermath of Patrick's reanimation, they have to resort to drastic measures to prevent the prison from being run over. Everyone's lives hang in the balance with the discovery of another deadly virus that threatens their lives.
Hershel tries to help those afflicted by the flu strain. On a supply run for medicine for the sick, Daryl learns about a so-called sanctuary that is being broadcast on the radio. Rick discovers the identity of Karen and David's killer.
While on their own supply run, Rick and Carol come across a couple but their attempt to help them backfires. Rick makes a decision about Carol's fate.
As the situation at the prison grows dire, Daryl's group races back with the needed medicine to treat the survivors. The Governor plots his revenge.
After Woodbury falls, the Governor finds his way to a small family after being abandoned by his men.
As the Governor makes a power play to get control of a new group of survivors, he comes up with a plan to take over the prison.
As the Governor launches his assault, he holds the lives of two members of Rick's group as leverage. The attack leaves the prison compromised, which threatens the lives of everyone inside.
As the survivors scatter after the prison is overrun, Rick despairs as he and Carl flee on foot. Michonne considers returning to her old life in the wake of the prison's fall, but ultimately makes a decision about her place in the world.
The rest of the survivors try to find safety in the wake of the prison's fall, slowly coming together as they learn about the fates of the others.
Glenn and Tara make a discovery about the possibility to stop the walker outbreak. Carl, Rick, and Michonne encounter a group called Claimers, which forces them out of their place of hiding.
Daryl and Beth's journey leads them to reflect on the past and set a course of action for the future, as Daryl helps Beth reach a milestone.
A disagreement causes Maggie, Sasha, and Bob to split as they consider heading for Terminus. Beth and Daryl encounter a mysterious group.
On the way to Terminus, Tyreese and Carol are forced to face the fact that one of their own party is unstable and might put the others in danger.
The paths of two groups of survivors intersect on the way to Terminus. Daryl comes to realize that the Claimers are hunting a familiar face.
Rick and the others have a confrontation with the Claimers. As everyone converges on Terminus, Rick comes to suspect that the so-called sanctuary has dark secrets.