Snow began to fall early on, and soon the world was reduced to the gray shadows of the dogs ahead, the lurching and creaking of the sledge, the biting cold, and a swirling sea of big flakes only just darker than the sky and only just lighter than the ground. Through it all the dogs continued to run, tails high, breath puffing steam. North and further north they ran, while the pallid noontide came and went and the twilight wrapped itself again around the world.
