Axel begs Rick to let him and Oscar join the group. Rick discusses this with the group. T-Dog is the only one who wants the prisoners to join but is unable to convince the others. While the group is admiring Hershel's determination to use crutches, they are surprised by a group of walkers moving through the prison compound, and the survivors are separated while fleeing for cover. Rick, Daryl, and Glenn return from outside the fences to find that the gate was left open and chains were cut, and Rick immediately suspects Axel and Oscar. However, when more walkers are attracted by the prison alarms, Rick's group has to rely on the prisoners to help them quickly find and shut down the generators. Oscar leads Rick and Daryl to the generator room, where Rick is ambushed by Andrew, who had lured the walkers in from the other side of the prison. Oscar gets Rick's gun and shoots Andrew, siding with Rick whose group he and Axel want to join. Meanwhile, T-Dog tries to close the gate that is releasing walkers and is bitten. He and Carol escape but soon are confronted by more walkers. T-Dog sacrifices himself to save Carol. Her head wrap falls off. Daryl later finds it, leading the group to assume she also was killed. Maggie, Carl, and Lori end up hiding in the boiler room. Lori goes into labor, but complications prevent a natural childbirth, so she insists that Maggie perform an emergency Caesarean section. Lori does not survive the procedure. Carl has to shoot Lori, his mother, in the head before she re-animates. When the group reunites, Rick hears the cry of a baby. Maggie and Carl appear, holding the newborn. Rick learns of his wife's death and collapses in mourning. Back at Woodbury, Andrea grows closer to The Governor and puts off a planned departure indefinitely, despite Michonne's increasing suspicions of the man.