A hilarious and heartfelt middle-grade novel about a STEM loving Black girl finding her place in the universe again after her first period knocks her out of orbit.

Rayana Johnson always thought that turning thirteen would mean being old enough to stay home alone, go on her first date, and attend Galaxy Camp, a sleepaway camp that's all about her true passion--space exploration.

But instead of having a blast on flight simulators and multi-axis trainers or learning what it takes to explore the stars, Ray's mind is stuck on Earth, wondering why her parents are arguing, why her best friend isn't acting like herself, and why her totally-crushworthy counselor keeps treating her like a kid. Then, just when things couldn't get any worse, puberty throws her the ultimate curveball--she gets her first period.

In the span of just a few days, Ray's gone from having total certainty in her universe to barely being able to count on anything--not her parents' marriage, not Galaxy Camp, and not even her own body. Will she ever feel grounded again, or is the rest of her life destined to be as nebulous as the Milky Way?