Dr. Hoffman turned to Sophie, his smile still glued on his face. She studied him. He was in his seventies, and his age showed. Even in the mild darkness, the creases on his face were visible, deep valleys above his glowing goggles. A cropped mustache lined his thin lips, and his smile revealed weathered teeth, stained by years of coffee drinking.

“Shall we, Dr. Winston?” he said, gesturing toward the building. “I know you are anxious to meet your team.”

“Yes, Dr. Hoffman. Please lead the way.”

Sophie followed her escort toward the building, her hand still noticeably shaking from their conversation. She could count the men who intimidated her on one hand, but Dr. Hoffman topped the list.

Up ahead, two monstrous blast doors screeched open. The entrance was carved out of the side of a mountain. Above the two doors was a single weathered sign that read, “Welcome to Cheyenne Mountain.”

“NORAD,” she muttered under her breath. She should have known. The ancient military facility was the perfect place for a biosphere. It had been used as the military’s aerospace defense command center in the early twenty-first century before it was decommissioned and fell into disrepair. She had been here once on a tour as a child, long before the solar storms scorched Denver. In the distance she could see the lights of Colorado Springs, which had barely avoided the radiation.

Dr. Hoffman shouted from the entrance. “Are you coming?”

“Yes, sir, just admiring the view.”

“I thought you were in a rush.”

“I am. It’s just this place brings back memories.”

“Ah, well be prepared for some . . .” He paused. “Changes,” he said with the same sly grin.

Sophie faked a smile and followed him inside the dark access tunnel, listening to the groaning of the blast doors closing behind them. The doors crashed shut, sealing them inside the mountain. Someone flipped a switch, and the hangar glowed to life, the lights clicking on one after another.

This was a different entrance than the one she visited. It was wide enough for a semi-trailer and built exclusively for the military, not for touring school kids. The bright overhead lights illuminated a small electric train that sat idle in the middle of the access tunnel like a carnival ride waiting for patrons.

“This way,” one of the soldiers said, opening the door to the train. Sophie followed Dr. Hoffman inside and took a seat on a metal bench.

“This train will take us to the most advanced biosphere ever designed by man. NTC has sunk a pretty penny into this facility. I trust you will find it acceptable for your research.”

“I’m anxious to start my work in the environment,” Sophie said, massaging her tender muscles. She crossed her legs and rested her back against the cold metal of the bench. Her neck was sore from where the chopper’s belt had cut into her flesh. She rubbed it, acknowledging that the aches were better than the alternative of perishing in a fiery wreck.