Causal Folding

In 2500, Earth's surface lies dead—humanity clings to survival in the suffocating depths below. Qin Zhen has known only loss: parents torn away by war, cities swallowed by environmental collapse, and the brutal fight for each breath in the underground ruins. But when he stumbles upon a mysterious mechanical artifact, everything changes. This relic doesn't just bend the rules of physics—it folds causality itself, rewriting past and future in impossible ways. Armed with technology that defies comprehension, Qin Zhen must navigate conspiracies buried deeper than civilization itself.