The bolt finally seated with a satisfying, solid thunk. Parisa exhaled, a cloud of vapor in the frigid air of the concrete pipe she’d called home for four nights. Her latest modification—a salvaged truck leaf spring as a locking bar for the interior grate—was complete. She pulled her spirit level from her belt and laid it across the bar. Perfectly horizontal. It didn’t matter that no one was here to see it. It mattered that it was correct. The pipe was dry, defensible, and now, with the bar, psychologically secure. Her inventory, scratched onto the wall with a piece of slag, was up to date. Now, the next problem: the condensation drip at the far end was threatening to create mud. She turned, level still in hand, her world narrowed to this seven-foot cylinder of order.