Iron Age: Deep Space Echoes

This story focuses on a human expedition that discovers a living old-age AI deep underground. But what is truly alive is not AI—it is humanity's own memory backup. The story is reversed on three levels: 1. The protagonist thinks he has found the "key to saving mankind", but in fact he is part of the key 2. The so-called alien invasion is a projection of the fear of humans in the old era about their own evolution being out of control. 3. In the end, the protagonist faces a choice: release memory (restore human civilization but lose personality), seal memory (retain humanity but live in ruins forever), or merge the two paths