I searched in vain for another glimpse of border wall, but the next two corners both led to other corridors, not the wall. My oxygen was running out. It was getting harder and harder to move my arms and legs.

The next turn didn't lead to border wall either, but I had no time to swim ahead and look for another corner. Summoning all of my energy, I swam down the short corridor and took the right turn at the end. That led to another short corridor. As I started down it, the rock slipped off my belly, scratching me as it fell. I yelped without thinking. Water rushed in, and air rushed out.

Coughing, I aimed for the ceiling to draw more air, but when I reached it, I found the water had beaten me to the punch — there was no more air.

I was treading water, silently cursing the fates and vampire gods. This was the end. I'd given it my best, but it wasn't meant to be. The best thing now would be to open my mouth, gulp in water, and make as quick an end of it as I could. I would have too, except this corridor wasn't well lit, and I didn't like the idea of dying in darkness. So, painfully, I dived again to the floor, gathered the rock, turned over onto my back, placed the rock on my belly, and swam ahead to find somewhere brighter to die.

As I made a left turn at the end of the corridor, I spotted the dark stone of border wall. I smiled weakly, remembering how excited that would have made me a few minutes ago. I rolled over onto my belly, so that I could die on my feet — then stopped.

There was an X on the wall!

I stared at it stupidly while precious air bubbles popped out of my mouth. Was this another trick of my mind? Another false crack? It must be. There was no way I could be this lucky. I should ignore it and…

No! It was an X!

I was out of air and strength, but the sight of that X gave me a new burst of life. Making use of resources I hadn't known I had, I kicked hard with my legs and shot towards the wall like a bullet. I bumped my head against it, recoiled, then rolled over and studied the large, rough X.