The Walking Dead: Book One pages 91-120

A few weeks later, Rick is teaching the group how to shoot, and most of his "students," especially Andrea, are getting very accurate.  Rick brings Carl, his son, to target practice, against Lori's dislike of the idea.  Carl, too, is a good shot, and Rick decides it's time for him to be able to carry around a gun like everyone else.  Lori loathes the idea of her seven-year-old son carrying around a gun, but Rick assures her that if Carl misuses it, it will be taken away.  The shooting group heads back to camp.

Rick, Dale, and Shane head out to split some wood, where they complain about Donna's behavior.  It is snowing, and Rick mentions something about it being cold, and Shane snaps.  He yells at him that everything will be fine, and goes back to camp alone.

Later that night, the group is sitting around a fire discussing what everyone did before the zombie breakout happened.  Dale says that he and his wife had been on the road for two years.  Amy was in college for physical education, and Andrea was a clerk at a law firm.  Glenn was a pizza boy who had lots of debt; he is somewhat relieved that he no longer has to pay for anything.  Allen was a shoe salesman and Jim was a mechanic.  Carol was a tupperware salesman.  Her husband died, and she and her daughter, Sophia, tried to go to Atlanta but fortunately never made it.

Amy gets up to go to the bathroom, and while she is asking if anyone needs something from the RV, a zombie comes from behind her and bites her in the neck.  Quickly, shots are fired and a horde gathers.  A struggle breaks out between the group and the zombies, and after everything clears, Andrea shoots Amy, saving her from becoming a zombie herself.  The group notices Jim sopping with blood, and he has a huge wound in his arm -- he was bit.

The next day, the group buries Andrea and holds a memorial for her.  Jim is in the RV, resting, where he is burning up and getting worse from his bite.  Meanwhile, Shane, Rick, and Carl are hunting and manage to shoot a rabbit.  Somehow, Rick and Shane get into another huge argument, blaming the whole thing on each other, and they scare Carl away.

Back in the RV, Jim has realized that what he wants is for the group to leave him behind.  Donna tries to resist his decision, but it's too late; they leave him behind forever.