After we piled into the elevator, I hit the R button, presumably for rooftop. Ellison and Mase cast me worried glances, the guard dangling between them, as the elevator began to rise.

A great thud over our heads rattled my teeth together. And then an even greater mechanical roar.

The three of us stared upward, frozen.

"This is the only way out?" Ellison asked, her voice shaky.

"Well, this is the way we're going," Mase said. "When these doors open, get ...