Moon is everything Christine isn't. She’s confident, impulsive, artistic . . . and though they both grew up in the same Chinese American suburb, Moon is somehow unlike anyone Christine has ever known.

But after Moon moves in next door, these unlikely friends are soon best friends, sharing their favorite music videos and painting their toenails when Christine's strict parents aren't around. Moon even tells Christine her deepest secret: that she has visions, sometimes, of celestial beings who speak to her from the stars. Who reassure her that Earth isn't where she really belongs.

Moon's visions have an all-too-earthly root, however, and soon Christine's best friend is in the hospital, fighting for her life. Can Christine be the friend Moon needs, now, when the sky is falling?