The smell hit first, like wet earth, mold, something rotten buried deep. It clung to their skin, filled their lungs. Leah pulled her scarf tighter over her mouth.

“This place reeks,” she muttered.

Jason’s headlamp flicked side to side as they crawled through the tight concrete tunnel. “Smells like something died in here twenty years ago. Maybe two.”

Leah crouched low, stepping carefully over a collapsed slab. “You sure this is the right path?”

“Kola’s map was precise,” Jason said, voice steady. “If we followed the red markings and dropped at the third pipe junction, this should lead straight beneath the plant.”

They moved like shadows. Each step took them...