Leah Lockhart is more than her astrology. She'll search the world to prove it.

Leah Lockhart is proudly science-minded and woo-woo averse. But the life she’s carefully curated is knocked suddenly off course, first by a destabilizing case of vertigo, and then by an astrology reading that claims she’s living way out of line with what was written in her stars.

Incensed, Leah sets off on a mission to prove that astrology is bogus by comparing her life to that of her Star Twins around the world—people born under her exact same map of the stars. But her even deeper guides on a whirlwind journey through Venice, Istanbul, New Orleans, and beyond turn out to be three people already in her orbit: the mother she thinks abandoned her, the father she thinks saved her, and the former boy next door whose love could be the path to her truest self.