Walker’s enthralling book covers the early stages of the space race, when the Soviet Union—despite the country’s utter devastation in World War II, in which 27 million Soviet citizens perished—demonstrated technological supremacy over the United States, the world’s richest and most advanced country. In 1961, the Soviet Union launched the first man into space. U.S. President John F. Kennedy, then newly in office, did not prioritize the space race with the Soviet Union; he was focused instead on Soviet meddling in Cuba. The Bay of Pigs invasion, which Kennedy secretly authorized, ended in a disaster just days after the Soviet cosmonaut Yuri Gagarin triumphantly orbited the earth. Walker’s narrative alternates between Soviet preparations for Gagarin’s flight and U.S. preparations for the United States’ first manned flight. It culminates in a suspenseful 50-page account of Gagarin’s 108-minute journey that reads in one breath. The Soviet space program was strictly classified. Gagarin’s name was first made public only when he was already in orbit; Sergey Korolyov, the program’s chief designer, was not identified by name until after his death in 1966; and some of the serious malfunctions during Gagarin’s flight remained secret until the Soviet Union’s collapse in 1991.