The story begins before the zombie outbreak has happened where sheriff's deputy Rick Grimes and his partner, Shane, are in a shoot-out with a prisoner who escaped jail in Grant County. Rick is shot in the chest, while trying to flank the prisoner which puts him into a coma. A month later, Rick wakes up in a hospital bed and finds himself in an abandoned hospital. He falls out of his bed and calls for help, but no one comes. After dressing himself, he explores the hospital, finding a corpse which falls backward into the opening elevator; as well as a cafeteria door that is blocked by a piece of wood. Rick removes the piece of wood and opens the door only to find multiple zombies inside the room. One of the zombies lunges at Rick which causes them to fall down a set of stairs where the zombie's head becomes decapitated.
Severely confused, Rick leaves the hospital (after locking the door with his belt to stop the other zombies) and finds a bicycle. As Rick walks toward the bike he sees a zombie that has deteriorated to nothing more than bones. At this sight, Rick temporarily breaks down. Shortly after, Rick returns to his home and finds that his house had been looted and that his family, Lori and Carl are gone. Upon exiting his home, Rick is knocked unconscious by a boy with a shovel. The boy's father quickly tells him that Rick is not a zombie and they bring him inside. Rick wakes up and has dinner with the man who's name is Morgan Jones. The boy that hit Rick in the head with a shovel is Morgan's son, Duane Jones. Morgan explains to Rick the nature of the outbreak, which started just over a month ago. Rick finds out that before the media shut down that the government told everyone to relocate to major cities. Rick decides that Lori would have taken Carl to Atlanta where her parents live. Rick, Morgan, and Duane go to the police station in order to get supplies. Rick gives Morgan and Duane some guns and a police car while changing into a police uniform and filling a bag with guns to take with him. Morgan and Duane decide to stay behind while Rick leaves in search of his family in Atlanta. The goodbye is interrupted when a zombie appears behind a fence and Rick nearly shoots it, though Morgan tells him not to waste the bullet and the two part ways. Later, Rick returns to find the severely decomposed zombie from earlier and puts it out of its misery before continuing on to Atlanta.
On his way to Atlanta, Rick's car runs out of gas and he is forced to scavenge for gasoline at a nearby home. Inside the home Rick finds the remains of a family that committed group suicide. After throwing up from the smell, Rick continues to explore the property where he finds a horse inside of a barn. Rick takes the horse as well as an hatchet as a weapon. Rick talks to the horse and starts thinking about how things were before the outbreak. He also reminisces about the day that his son Carl was born. Rick realizes that thinking about the good old times make the outbreak seem much worse.
Rick arrives in Atlanta and enters the city to find it in ruins and overrun by zombies who swarm him and knock him off his horse. As he sees his horse being eaten by zombies he begins shooting and trying to escape the zombie onslaught. He runs into an alley where he meets a supply runner named Glenn. Glenn tells Rick to stop using his gun and to follow him. Rick and Glenn exit the city safely. Glenn explains to Rick that everyone in the city died in under a week and Rick momentarily breaks down thinking that his family has been killed. Glenn then explains to Rick that there is a camp outside of the city where there are a group of survivors and that his family might be there.
When Rick and Glenn get to the camp, Rick is reunited with his wife, Lori, and his son, Carl. He is also reunited with his partner and best friend, Shane who has been protecting Rick's family since the outbreak. Then Rick is introduced to some other survivors known as Allen, Dale, Jim, Carol, Sophia, Amy, Andrea, Donna, Billy, and Ben. Allen and Donna are husband and wife and Ben and Billy are their twin boys. Carol is the mother of Sophia. Amy and Andrea are sisters. Lori explains to Rick what happened during Rick's coma as well as how they set up camp when they found Atlanta impossible to enter. That night, Rick and Lori talk about everything that has happened and Rick admits to how scared he actually is.
The next day, Dale tells Rick to be careful around Shane because he thinks Shane is in love with Lori and that Shane isn't happy about Rick being back. Rick and Shane go hunting while Lori, Donna and Carol wash the laundry. Rick and Shane study a zombie eating a deer. Meanwhile, as the women go back towards the camp after finishing their laundry, they are attacked by a zombie. Dale decapitates the zombie before it bites Donna, but they find that the head is still alive. The zombie that Rick and Shane were studying suddenly attacks them. Rick hits the zombie in the head with his axe. The two men hear a gunshot and race back to camp. Lori cries to Rick and relays story concerning the zombie attack. It is revealed that Shane does indeed love Lori when he sees Rick and Lori hugging, now jealous. Later that night Rick and Shane talk about moving the camp to a safer area. Shane argues that they aren't moving the camp because if the government starts cleaning up the outbreak, the government would start with a major city and they would be found sooner. Rick finally agrees not to move the camp, but insists that they need to find more guns to protect themselves.
The following day, Rick asks Glenn if he could come with him to get supplies in Atlanta. One of the purposes it to obtain firearms for the group. Jim, who happens to be the sole survivor from Atlanta, tells them the location of a gun store which is five blocks from where Rick and Glenn first met. Rick has an idea. He takes Glenn to the zombie that he and Shane had studied the day before. Rick's theory is zombies don't attack each other because of the stink of death. His plan is to rub the zombie's body parts on their clothes so that they will smell like the zombies. The plan works and they are able to go deeper into the city to obtain the firearms. While exiting the city, it begins to rain which washes away the zombie stench off. This causes an attack by the zombies. A zombie bites Rick on the shoulder as they make their escape from the city. Safely outside of Atlanta, Rick checks his shoulder only to realize that the zombie hadn't bitten through his jacket. As they head back to camp with the guns, Rick tells Glenn not to tell Lori about the zombie attack. Meanwhile, Shane and Lori talk discussing Rick going into the city. Shane wants to come inside out of the rain and offers to "keep her company". Lori rebukes him and says that he needs to stop this now that Rick is back. Shane asks Lori about the night they spent together on their way to Atlanta (strongly hinting that they had sex). Lori tells Shane that night was a mistake.
Over the course of the next couple of weeks, the group have target practice with the guns that Rick and Glenn brought back from the Atlanta gun store. Andrea quickly proves that she is the best shot in the group. Rick allows Carl to practice which causes a disagreement between him and Lori. Rick, Shane and Dale later discuss Donna, who has been complaining about Andrea and Amy staying in Dale's camper, and the upcoming winter while chopping firewood. Shane yells at Rick to shut up about everything, leaving Rick speechless. While eating dinner that night Rick asks the others what their lives were like before the outbreak. Dale says that he was a retired salesman who was traveling with his wife in their RV when the outbreak came. Dale's wife died in the initial outbreak while they were at a campsite leaving Florida. After burying her, Dale came to Atlanta to find his cousins. He met Amy and Andrea stranded because their car had ran out of gas. Andrea was driving Amy back to college so that they could have some bonding time. Andrea had a job as a clerk at a law firm. Glenn was a pizza delivery boy who was swimming in debt and was nearly forced to ask his estranged parents for money when the dead started rising. Allen was a shoe salesman in a mall who was also struggling to make ends meet. Jim simply says that he was a mechanic. Finally, Carol talks about how her husband, a successful car salesman, committed suicide when he saw his parents being eaten by zombies. She also implies that he was abusive and simply convinced her to stay with him long enough to care for Sophia. Amy goes to the RV to use the bathroom when she sees a zombie which forces her to unknowingly back up into another zombie which bites her in the neck and kills her. The survivors are attacked by a group of zombies which they are able to fight off. Carol and Sophia are saved by Glenn as Andrea grieves over Amy's body, oblivious to everything. Lori is nearly killed by a zombie, but is saved by Carl who shoots the zombie. Jim launches into a rage and attacks a zombie while yelling at it saying that it killed his family. When all the zombies are dead Andrea shoots Amy in the head in order to prevent the reanimation. It is then revealed that Jim was bitten in the arm when he killed the zombie, though he says it is just a scratch.
The next day a funeral is held for Amy. Shane, Donna, Dale and Rick all take turns eulogizing her and Jim has perhaps his biggest speech, saying that nobody deserves this kind of death, especially a nice girl like Amy. Andrea is in a depression and Jim falls desperately ill. Meanwhile, Rick, Shane and Carl go hunting and Carl tells Rick that they don't need as much food because Amy is dead and that Jim is too sick to eat. Shane yells at Rick saying it wasn't his fault. When they return, Donna informs them of Jim's request to leave him outside of Atlanta. Jim hopes that once he turns, he can reunite with the zombified members of his family. The group bring him to the outside of Atlanta to say goodbye. The following day Shane tells Rick to get ready to go hunting. Rick tells Carl to stay behind so that he and Shane can talk. Shane starts yelling at Rick and punches him. Lori then punches Shane which causes Shane to mentally snap and run off. Rick goes to follow Shane and Carl follows his father in turn. When Rick catches up to Shane, Shane starts yelling at Rick about how Shane just lost his respect and how Lori would have changed and loved him if Rick hadn't returned. Shane then points his gun at Rick and is about to shoot him when Carl shoots Shane in the neck. Shane died choking on his own blood. The book ends with Carl saying "It's not the same as killing the dead ones, daddy" and then Rick replies saying that, "It never should be, son, It never should be."
Lori Grimes is having a flashback to the beginning of the outbreak, where she's waiting outside of Atlanta in a jammed line of cars, where she is confronted by Shane. Lori expresses her regret about leaving Rick behind at the hospital but expresses comfort about how Shane accompanied them. The two of them end up having passionate intercourse on the grass not far away from their car.
Back to the present, the survivors are burying Shane. Rick is still in shock over Shane's attempt to murder him and expresses worry about the mental stability of the rest of the group. Lori spits on Shane's grave. Dale then tells Rick that the group want Rick to be their new leader. Dale talks with Rick about Shane and tells him that Andrea thinks Christmas is coming up. Rick immediately tells Dale that he wants to skip Christmas this year so none of the kids get upset. Rick asks Carl if he wants to talk about what happened with Shane, but Carl doesn't say anything. The group then departs from their camp using the RV. They continue on their journey until they need to clear some cars that are blocking the road. While clearing the cars, the group are surprised by the sudden arrival of Tyreese, his daughter, Julie, and her boyfriend, Chris. Rick nearly kills Tyreese after mistaking him for a roamer, but the group quickly allow the new arrivals to join them. Lori is not happy about this and tells Rick not to be so trusting of other people, even if they have kids with them. The next morning, Tyreese and Rick are discussing how the apocalypse has drastically changed them and the people they know. Tyreese explains to Rick that a few weeks ago, while scavenging a nearby country store for supplies, an old man who was supposedly the nicest old man anyone could ever meet had been living in the store and attempted to rape Julie. However, he was able to kill the man before he could rape her. This reveals that, similar to Rick, Tyreese is willing to do what is necessary in order to survive, regardless of how gruesome it may be. Tyreese feels that the apocalypse has changed him even more than it had changed the old man as he feels no remorse for killing him. Rick later explains to Tyreese the names they gave zombies which were roamers (who are always on the move) and lurkers (who are content with sitting around all day until they smell or see food nearby) because not far ahead they see two roamers heading toward the group, Rick and Tyreese quickly and quietly kill the zombies, Rick uses his axe and Tyreese uses his hammer. The following night, the other group members are quickly warming to Tyreese especially Carol who starts to flirts with Tyreese, he evidently returns the feelings. Lori reveals to Rick that she believes she is pregnant and then she tells the group that she is pregnant. Everyone is happy for the Grimes family but they are all worried because of the lack of doctors and medical care. Dale quickly confronts Rick about the fact that the baby might be Shane's based on the timing, but Rick cuts him off saying that he is aware of it but he can't bear the thought or he will lose his mind.
The group continues on their journey until they come across a group of houses enclosed by a fence, titled "Wiltshire Estates." The group decide to stay there since they think they will be able to start a new life there. Tyreese and Rick proceed to clear a house but Rick is attacked by two zombies. Tyreese hears Rick shouting for some assistance and Tyreese football tackles one of the zombies that was about to kill Rick. After they kill both zombies Tyreese reveals details about his past as an NFL player. This house that Tyreese and Rick cleaned out is loaded with canned goods and there are enough rooms for everyone to bunk with their families which leads them to think that they may have found a permanent sanctuary. They end up spending the night inside the cleared house. What they don’t notice is a snow covered sign at the entrance to the enclosure that reads "ALL DEAD DO NOT ENTER".
In the morning, Rick and Lori are discussing how Carl is handling their situation and also about how they are going to give the baby a happy life. Donna talks with Allen about how happy she has been lately, having taken hope from seeing Dale and Andrea overcome their losses, their new sanctuary and that they couldn't have found nicer neighbors. The group plans to split and clear each of the houses. Rick notices the sign while fetching a gun for Tyreese and, shortly after, the group is attacked by a big group of lurkers which had been hiding in the houses. Donna is killed in the attack, leaving Allen devastated. He wants the group to leave him behind but is convinced otherwise by Rick who tells him to think of his children, Billy and Ben. Tyreese and Rick return to the house for Chris and Julie (finding them on the verge of having sex) and they all manage to escape the massive horde by jumping on the roof of the RV. The group then narrowly escapes from Wiltshire Estates in the RV. The survivors continue on. Rick and the others show concern for Allen's deteriorating emotional state. As the group's food supply begins to diminish, Rick, his son Carl, and Tyreese go hunting for some food. During the hunt, Carl is accidentally shot by a farmhand called Otis who mistakes them for zombies. Rick nearly kills Otis in a fit of rage before realizing that Carl is still alive. Otis informs them that one of the people at the farm where he has been staying has medical experience. Otis leads Rick to the farm with Carl as Tyreese informs the group of Carl's accident.
At the farm, Hershel Greene manages to extract the bullet from Carl and save his life. Hershel invites the group to stay while Carl recuperates and introduces the group to his children: his oldest daughter Lacey Greene, his son Arnold Greene, his daughter Maggie Greene, and his youngest son Billy Greene. Hershel also introduces his twins Rachel Greene and Susie Greene, Otis, and Otis's girlfriend, Patricia, who live up the road but are staying with Hershel and his family since Hershel's home is more safer for them.
As the group settle in, Andrea tries to talk with Allen about getting over Donna and not shutting down for the sake of his sons, but this just makes Allen extremely angry. Sophia is relieved that Carl is fine and pecks him on the cheek. Dale talks with Lori about the fact that her baby might be Shane's but does not want her to tell Rick as Rick is the one stable person in the group and is needed to be their leader. After dinner, Glenn talks with Maggie about how he feels sorry that he didn't try to talk to Carol sooner and maybe start a relationship with her as he doesn't want to be alone forever. Maggie agrees to sleep with him as she doesn't want to regret anything either. Hershel converses with Rick about a permanent place for the group to sleep but tells Rick that he doesn't want to sleep in the barn as that's where he's keeps all his dead ones. Hershel explains to an angry Rick about his views of the zombies as still being living people and not wanting to kill them in case they suddenly turn back to normal, and he explains that his eldest son, Shawn Greene, is in that barn with also many neighbors and random zombies that wandered onto Hershel's Farm.
The following day, the group is practicing how to shoot firearms when Hershel stops them because the Thompson house is getting riddled with bullets across the way. A zombie then appears and Hershel attempts to get the zombie inside the barn. As Hershel opens the barn, a zombie suddenly falls through and opens the barn doors all the way, allowing all the trapped zombies to break out. Arnold saves his dad from being bitten but is bitten by his zombified brother. The group begins to kill the zombies as Lacey is torn apart by a few of them. Finally seeing that his son will never be normal again, Hershel takes Maggie's gun and shoots his three children to prevent reanimation. He briefly puts the gun to his own temple but is stopped by Rick.
The next day, Hershel discovers Glenn sleeping with Maggie and gets into an angry argument with her, but he leaves them be for the time being. Rick and Allen talk about Donna while cleaning up the barn to sleep in. Rick asks Hershel if they can sleep in the house, but Hershel angrily tells Rick that he expects the group to leave the farm soon. Lori angrily confronts Hershel, saying that Hershel is sentencing them to death by forcing them out. Hershel maintains that he has to look out for his own family and eventually puts a gun to Rick's head to force them to leave. The group finally decides to leave Hershel's farm. Otis tries to talk with Hershel who is now convinced that he has lost his mind after nearly killing Rick. Glenn stays behind to pursue his relationship with Maggie. After some unsuccessful raids and hunting parties, and the group becoming increasingly starved, Dale and Andrea stumble upon an abandoned prison. Rick tells the group that they can clean it up and make a life here, and pronounces it home.
- Bicycle Girl (Zombified)
- Reggie (Alive and Zombified)
- Arnold Greene
- Lacey Greene
- Shawn Greene (Zombified)