Sixteen-year-old Callisto May feels a deep connection to astronomy. She can name all the moons of Jupiter and even tell you the dimensions of the Great Red Spot. But she feels completely alone on planet Earth. And now that she's pregnant, her loneliness is acute. She can't turn to her mother, who's always been too consumed with unspoken grief to care for her children; she can't turn to her father, who buries himself in work and pretends that life at home is normal; and her surfer boyfriend wants freedom to catch the perfect wave more than he wants to hang around Callisto. Only Callisto's little brother loves her unfailingly, but she can't be there for him right now. She's got to make a huge decision - and, for a change, that means thinking of herself first. Somehow, though, as her world orbits out of control, Callisto finds the courage to fight through the secrecy and silence that are suffocating her family, along with the strength to decide what's best for her future.