In the shadow of the Cold War, whispers from the cosmos fueled an unlikely alliance between the US and USSR. The search for extraterrestrial intelligence (or SETI) emerged as a foundational field of radio astronomy characterized by an unusual level of international collaboration—but SETI’s use of signals intelligence technology also served military and governmental purposes. In this captivating new history of the collaboration between American and Soviet radio astronomers as they sought to detect evidence of extraterrestrial civilizations, historian Rebecca Charbonneau reveals the triumphs and challenges they faced amidst a hostile political atmosphere. Shedding light on the untold stories from the Soviet side for the first time, she expertly unravels the complex web of military and political interests entangling radio astronomy and the search for alien intelligence, offering a thought-provoking perspective on the evolving relationship between science and power. This is not just a story of radio waves and telescopes; it's a revelation of how scientists on both sides of the Iron Curtain navigated the complexities of the Cold War, blurring the lines between espionage and the quest for cosmic community. Filled with tension, contradiction, and the enduring human desire for connection, this is a history that transcends national boundaries and reaches out to the cosmic unknown, ultimately asking: how can we communicate with extraterrestrials when we struggle to communicate amongst ourselves?