Snowflakes like little, flat shards of glass were drifting in the air, hanging still, slicing sideways, twirling and flipping, slowly working their way to pavement as if from giant windows shattered thousands of feet above. The earth, some immense greenhouse in space, its air kept in by an enveloping lattice of glass. I imagined all the world’s air leisurely escaping in the night, through a single missing pane. In the morning the whole world would wake up in a vacuum, our only warning these few delicate fragments fluttering their way to the ground.