"For if a man yet lives, death has not arrived; if he has ceased to live, death is past" St. Augustine
So when is one dying?
DeLillo is concerned with this question. When is one dying if one is either living or dead. When does the process of dying happen? He borrows twice St. Augustine “And never can a man be more disastrously in death than when death itself shall be deathless” in Americana and once again in Zero K. He portrays the process of “dying” with Artis, the stepmother of the narrator. Jeffrey Lockhart comes to a cold place with no identity to comfort his father who has to watch his wife die. She is the dying.
DeLillo never finds the answer to when one is dying because it is a process that goes hand in hand with life. Jeffrey is the living entity in the novel. He is young and has no suicidal thoughts, but at the same time, his life is so empty that he is not really living. Artis wants to live but her body is failing her so she has to be kept “alive in death” in order to be resurrected in the future. Ross, Jeff’s father, is a healthy man even if he is old, but he seems to be more dead than Artis because he cannot consider a life without her.
So the story,imo, revolves around one’s position vis-à-vis death. Everyone is partly dying in a way or another.