Lifted skyward on a pillar of fierce heat from the shattered core, convoyed by obliging winds, the invisible cloud of radiation had traveled thousands of kilometers since its escape from the carcass of Unit Four. Unleashed in the violence of the explosion, it had soared aloft into the still night air, until it reached an altitude of around 1,500 meters, where it was snatched by powerful wind currents blowing from the south and southeast, pulled away at speeds of between fifty and a hundred kilometers an hour, and flew northwest across the USSR toward the Baltic Sea.
