The rare remembered dream

Half-submerged steel city in the shadow of a broken bridge, its clockwork parts askew.
I am leading an expedition through rusty water that stains our shins and ankles. Reaching the entrance, we crawl, foot-to-head, through the sandbagged tunnels.
If you want light you must touch the walls just so.
We come out into a maze of thin streets, rimed with old graffiti. No sky. Just ceiling A barefoot figure turns a corner, then darts into a hidden door.
"You never knew people lived here, did you?"

Wake.