A chair sat on a square of plywood on the dirt floor of the tunnel. A real estate flyer, a pornographic magazine and an empty box of antidepressants formed a poignant tableau. Soon, the tunnel ended at a verdant slope leading up to the city streets. We had no idea where we were, and the neighborhood seemed a little rough. A group of kids taunted us and threw rocks as we reentered society. "It's a hazardous profession," Solis said, as we headed for the tall buildings visible across the river.