To Sulu, it felt as if the air around him had become filled with a sort of dark energy.

The higher they climbed, the cooler and thinner the air became.

He realized that the air had become a bit stuffy, yet it seemed like a complete change now.

He hadn't realized how stale the air in the cabin had become.

And the higher you flew the more turbulent the air became.

Outside, the air had become still, as if exhausted by the heat of the day.

Ultimately, the air itself would become cold enough to condense and fall as snow.

On the second day past the island, the air had become thick and a storm came down from the north.

The farther she moved into the warehouse, the heavier the air became.

They kept people there and they died as the room's air became without oxygen.