What is the climax to the short story called "By the Waters of Babylon"?
A large part (most) of the story is about John's journey to the forbidden east. He is not supposed to be going east, because that is where the place of the gods is. Much of the time the reader is just as clueless as John is in regard to what exactly is the place of the gods. Eventually the reader is able to figure out that the place of the gods is New York City. John is amazed at the tall buildings and massive bridges. As he is searching the city, John enters a condo or apartment and is exploring all of the rooms and appliances. He simply doesn't understand what he is looking at.
In the washing place, a thing said "Hot" but it was not hot to the touch—another thing said "Cold" but it was not cold. This must have been a strong magic but the magic was gone. I do not understand—they had ways—I wish that I knew.
John soon falls asleep and has a dream (vision) of the past. He sees New York City all lit up and people rushing all over the place. Basically, John sees New York City as it is now. That dream sequence is the climax to the story. It's completely overwhelming to him, but more importantly it is the main turning point in the story. The dream gives him knowledge that gods didn't live in the city. People lived in the city. Everything after that dream sequence, which isn't much, is falling action and resolution.