Rick searches for his family after emerging from a coma into a world terrorized by the walking dead. Morgan and Duane, whom he meets along the way, help teach Rick the new rules for survival.

Rick unknowingly causes a group of survivors to be trapped by walkers. The group dynamic devolves from accusations to violence, as Rick must confront an enemy far more dangerous than the undead.

After returning to the camp with the department store survivors and an emotional reunion with his wife and son, Rick decides to go against Shane's advice and go back to Atlanta for Merle Dixon and his dropped bag of guns accompanied by Merle's younger brother, Darryl Dixon, as well as Glenn and T-Dog.

While still in search of Merle, the group tries to retrieve the bag of guns but are attacked by several living men who are also after the weapons. The group manages to grab the injured attacker; however, several of the attackers escape and take Glenn hostage. Back at camp a large group of walkers venture up the hill and take the survivors by surprise.

Rick leads the group to the CDC after the attack on the camp. Jim must make a terrible life and death decision.

Rick and the group are allowed into the CDC by a strange doctor, but all is not what it seems in their newfound haven.