Sheriff Rick Grimes is critically wounded in the line of duty and fall into a coma. When he awakens, he is horrified to find that the world has been devastated by the dead having come back to life and the living are now clinging to the outskirts for survival. He sets forth to trek a virtually dead landscape in hopes of finding his wife and son.
Rick's discovery of new survivors is bittersweet as they are kept from returning to their camp by a horde of walkers. However, the most dangerous threat maybe not from the dead, but from the living.
Rick arrives at the survivor camp where he is reunited with his family. Unfortunately, this leaves Shane, who's been filling Rick's role, on the outside. Things get worse when Daryl returns to camp and hears that his brother was left handcuffed on a roof.
Rick, Glenn, T-Dog, and Daryl move on after their grisly discovery to retrieve the guns when they encounter a group of scavengers who narrowly beat them to the catch. However, Glenn is kidnapped in the scuffle, which leads to a tense stand-off and a surprising discovery.
Meanwhile, back at camp, the group has to handle a serious situation when Jim begins acting unhinged.
Everyone deals with the fallout of the walker attack. Andrea has to come to grips with the fate of her sister, while Jim is found out to have been bitten. With the camp clearly no longer safe, a decision must made about the direction they are to take.
The survivors find a safe haven at the CDC. With all the creatures comfort that they could call home, it seems a perfect place to rest. However, the lone scientist, Dr. Jenner, knows something that he isn't telling them.
Rick leads the group out of Atlanta. On the highway, they are stopped by a threat unlike anything they have seen before. The group searches for someone who has gone missing.
Coming to the aid of another, Rick discovers a possible safe haven. Shane must go on a dangerous mission to get badly needed medical supplies.
The group desperately awaits Shane's return. Shane finds himself trapped in a school, surrounded by the undead. Daryl and Andrea search for someone in the woods.
Shane makes a deadly sacrifice which leads to unusual behavior and self-distancing. The rest of the group tries to hang on somewhere between living to die and dying to live.
Concerned for their safety, the group makes a plan – one that Hershel disagrees with adamantly. He makes it clear the group is fine to stay for now, but not indefinitely.
Secrets are told and secrets are revealed. Hershel refuses to acknowledge the world’s new reality. Andrea comes out of her shell. Everyone is becoming more and more aware that “everything is food for something.”
Hershel sets a deadline. All secrets are out in the open. Glenn stands up for himself and Shane takes charge.
After the barn, there is much conflict among both groups of survivors, Hershel wants Rick and his group to leave immediately and Shane accuses Rick to be just as delusional as Hershel saying that Hershel knew about Sophia the whole time and hid her from the group. Dale tells Andrea to be careful about her relationship with Shane since Dale knows what kind of person Shane is and now wants him gone from the group. He also reveals this to Lori, including the fate of Otis.
Trapped, Rick, Hershel and Glenn fight to survive against new foes, both dead and alive. Shane finds Lori in danger on the road and makes it his mission to bring her back to the farm.
Rick and Shane come into conflict over the fate of an outsider. Andrea helps Hershel's youngest daughter face a crucial decision.
Rick sides with Shane causing Dale to worry that the group is losing its humanity; Carl's actions have unintended consequences.
The group learns that someone dangerous may be on the loose near the farm. As night falls, Rick, Shane, Daryl and Glenn comb the woods to handle the situation and keep the group safe.
Rick and Carl find the farm in jeopardy; the group is split up in the chaos; Rick's leadership is questioned.