...there's a place in the tunnels outside the north block. We just call it the Pillar. We don't know what it is, or why it's there; it's just a pillar of stone in a pool of glowing water.
Sometimes, it calls to people who give up or can't go on, and they go to find it. When they get there, they merge with it, and become stone. Sometimes people come back...but they're never quite the same. Sometimes they forget everything. Sometimes they don't, and that's worse for them.