To pay off his gambling debts, the Great Tsar of Russia is obliged to sell Alaska. Henry Seward, the American Ambassador, whose patriotism is quasi-religious, is in charge of negotiations. He contacts Lucky Luke to escort him (and the funds!) to Alaska. Ralph Bargain, an unscrupulous businessman whom Seward regards as a faithful friend, is travelling with them. Bargain's sole interests are personal profit, and he means to recuperate the sale money for himself. Luke's journey to Alaska is rife with Russian revolutionaries, ambush attempts and even an intransigent polar bear!