A coded message is smuggled out of Russia, a plea for help from the director of a super-secret laboratory deep in the frozen wastes of Siberia. The note is addressed to Johnny Porter, a Canadian Indian of the Gitxsan tribe with a genius for languages. The CIA recruits Porter, who infiltrates Russia, first posing as a Korean sailor on a tramp freighter, then as a Chukchi driver called Khodyan. Working at a transport company, he befriends an employee who gives him sufficient spare parts to build a bobik truck, which he assembles in a cave. Porter also befriends the local doctor, Tanya Komarova, who is also working for the CIA, and they become lovers. With her help, he infiltrates the research facility by switching places with an Evenk employee. The director, Ephraim Rogachev, reveals to Porter the research they have been conducting, including a cure for blindness which the Soviets are concealing because of the military applications of the technology.
The Russian security services become aware that "Khodyan" is not who he says he is, and begin to pursue him. Porter escapes, first in the bobik, then by stealing a plane ticket, a snow-plough, and finally on skis. He makes his way to the Bering Strait where the Soviets finally catch up with him. He escapes to America, but suffers severe wounds including the loss of an eye.
The Americans fake his death, and he sends a message to Komarova to join him.
