Pitch Black

You reach out and feel for anything. There are walls on either side of you but they're covered in some kind of cold slime. You can feel tiny ridges between where the bricks meet, but they're not enough to hold on to. They're flying by too quickly to even bother with. Actually grabbing on to anything would dislocate bones and break joints.

For a moment you feel like you're slowing down. Then you hit the bottom.