Holden's sense of smell isn't nearly as good as Laura's, but he still gets a sense of the space below them — of air that's been closed off for a very long time, probably with good reason. Who knows what they might be awakening down there? But

he looks back sharply at the sounds of crashing behind them, has maybe a second to recognize the blockage of their way out before he sees the ground begin to shatter beneath them. He pulls at Laura's arm with a free hand, then gives Ellis a push, quiet signs to hurry.

"Go!"