Doomsday Legend: I Build the Infinite Train

My name is Lin Feng, and I'm a mechanical engineer. It was an ordinary morning; sunlight streamed through the window into my workshop, and I was intently repairing an old engine. As a mechanical engineer, I was used to dealing with metal, engine oil, and electrical circuits, used to restoring broken things to their original condition. However, that day, everything changed. The sky suddenly cracked open, as if a giant pane of glass had been shattered by an invisible force. I looked up at the window and saw dark clouds churning, and black cracks appearing on the horizon, like some unknown force tearing at something.