The Grand Duke has lost his life aboard a train racing through the northernmost reaches, and everyone is under suspicion. There is the Grand Duchess "Sophia," obsessed with specimens and indifferent to her husband's death; the elusive train conductor; and Prince "Ivan" accompanied by "Special Envoys" carrying secret orders. Guest must find the true culprit as quickly as possible. Guest knows. When this train stops again, all secrets and truths will melt away and vanish, just like the wind and snow trailing behind them.

Waking up in the morning and looking out the window, you see the world outside is engulfed in a heavy blizzard. Although the room is heated, the warmth seems to have vanished following the incident that occurred yesterday.