The World Government suppresses information of the planets outside Earth. Armed only with an illegal spacecraft, forbidden knowledge, and her own wits, Lyra Cartier, the last living descendant of the great navigator, leads a daring expedition to bring knowledge of the outside world to the population of Earth. Cartier leaves home at great risk. Even if she does return alive, she will be an enemy of the state, and will live her life as a pariah. But Earth could be enlightened, and Cartier will stop at nothing.