On the evening of the twenty-ninth day of the twelfth lunar month years ago, Mr. Guo, the father of Guo Lin, suffered a heart attack at the station and fell to the ground. He was later rescued by someone and taken to the hospital.
By the time Guo Lin arrived at the hospital, Mr. Guo had already regained consciousness, but he kept muttering about a "Gatekeeper" he had seen at the brink of life and death, implying that he had glimpsed the world beyond death, and he believed that Guo Lin's late mother was in that world.
Guo Lin knew that his father had a military background and was very stubborn, having always dismissed superstitions. Nevertheless, he speculated that his father's surrealist claims were probably hallucinations induced by his near-death experience, which had left a profound impression on him.
It's not at all strange that such life-threatening situations can produce hallucinations that undermine previous understandings of reality.