Ambitious Roman astronomer Gaius Crassus shocks the world with his announcement of a new planet in the night sky. Under the tutelage of the sardonic Ptolemy, he embarks on a journey of scientific discovery and personal growth in the Alexandrian heat, until the discovery of a mysterious artifact cuts short his efforts to vindicate his theory. Centuries later, a bright young Oxford graduate student rediscovers the truth about the planet Juno, finally proving Gaius right. A wild theory leads her to the banks of the Nile to find the very same probe that Gaius and Ptolemy first uncovered nearly two thousand years earlier. Meanwhile, on the rogue planet Chy'alos, long ago ejected from its own solar system, a brilliant engineer grapples with the millennia-long task of arresting his planet's momentum to place it in a stable orbit around a new star. As this project draws to a close, the chyret race, emerging at last from an era of uncertain doom in the infinite void, find themselves faced with a new challenge; neighbours. Rogue blends hard sci-fi with Rome, romance, and irreverence; it meanders through love and religion while addressing with rigorous, grounded precision the technical and physical demands of building a planetary engine powerful enough to circularise a highly elliptic orbit around a new star.