“I merely ensured the test went uninterrupted,” Thorne said.

He pulled his hand out of his jacket.

He was holding a small, black electronic device with a single digital display.

The numbers on the screen were counting down.

04:12.

04:11.

“What is that?” Whitmore screamed, backing away toward the cabin door.

“The ventilation override,” Thorne said. “In four minutes, the recirculated air will seal completely.”

“You’ll die too,” I said.

“I have the antidote in my pocket, Grace,” Thorne said, his voice deadly quiet. “But only enough for one.”

The cockpit phone on the overhead panel suddenly began to ring, its loud, electronic chime filling the small space.

The blue light on the overhead panel flashed in tandem with the chime.

It was London Center.

“Don’t touch it,” Thorne said, pointing the device toward me.

His hand was steady, his fingers pale against the black plastic.

“Grace, what do we do?” Malachi asked, his voice cracking.

He kept his eyes on the attitude indicator, his small hands gripping the yoke.

“Keep flying the plane, Malachi,” I said, trying to keep my own voice level.