Several months have passed and Rick and the expanded group are living a more peaceful life at the prison. Problems surface when Rick encounters a new survivor, and a supply run ends in disaster.

Rick is forced to abandon his quiet lifestyle when a mysterious virus puts the lives of everyone at the prison at risk.

As the sick are quarantined, Daryl, Tyreese, Michonne and Bob leave the prison in search of medical supplies. Rick makes a shocking discovery.

Daryl, Tyreese, Michonne and Bob continue to the veterinary college on foot in search of medicine. Rick and Carol go on a run to a nearby town where they find two uninfected stragglers.

Hershel struggles to care for the sick as the situation in the cell block escalates. Meanwhile, Rick and Carl defend the prison as the fences give way.

The Governor bonds with a small family following the downfall of Woodbury.

The Governor plans his next move as he, Lilly, Tara and Meghan adjust to new surroundings.

With the prison overrun, Rick and Carl find themselves on the road looking for shelter. Meanwhile, Michonne is haunted by memories of the past.

Beth tries to remain hopeful. Tyreese, Lizzie and Mika run into a familiar face. Glenn and Maggie struggle to cope without each other.

While Carl and Michonne look for supplies, Rick is faced with a gang of marauders. Meanwhile, Glenn and Tara are brought together with three strangers on an important mission.

Daryl and Beth seek refuge in the woods, where conflict emerges between the pair.

Maggie, Sasha and Bob clash over whether they should head to Terminus. Daryl and Beth take shelter in a seemingly abandoned funeral home.

Carol has to cope with old secrets and Lizzie's psychotic behavior when she, Tyreese and the girls take refuge in a vacant house on the way to Terminus.

Glenn and Tara are set on the way to Terminus, but Abraham is reluctant. Daryl struggles to adjust to the Claimers' rules.

Rick, Carl and Michonne cross paths with the Claimers once again on the way to Terminus, as the so-called sanctuary begins to reveal its true face.