Deputy Sheriff Rick Grimes awakens from a coma, and searches for his family in a world ravaged by the undead.

In Atlanta, Rick is rescued by a group of survivors, but they soon find themselves trapped inside a department store surrounded by walkers.

Rick is reunited with Lori and Carl but soon decides - along with some of the other survivors - to return to the rooftop and rescue Merle. Meanwhile, tensions run high between the other survivors at the camp.

After the attack on the camp, Rick leads the survivors to the C.D.C., in the hope that they can cure an infected Jim.

The survivors gain access to the C.D.C. in the hope of a safe haven.