This was a twenty-four-hour news network. The crawl running across the bottom of the screen was being updated every few minutes by the current BFR, or Bolide Fragmentation Rate, which had started out at zero on A+0 and been climbing ever since then; this was the number that, when it caromed through the bend in its exponential curve, would signal the onset of the White Sky. The networks had been tracking it obsessively. There was an app for it. A bar in Boston had begun offering end-of-the-world drink specials whenever the BFR broke through certain milestones, and the promotion had been copied widely.