It's the summer before eighth grade, and Erica "Chia" Montenegro is feeling so many things that she needs a mood ring to keep track of her emotions. She's happy when she hangs out with her best friends, the Robins. She's jealous that her genius little sister skipped two grades. And she's passionate about the crushes on her Boyfriend Wish List. And when Erica's mom is diagnosed with breast cancer, she feels worried and doesn't know what she can do to help. When her family visits a cuarto de milagros, a miracle room in a famous church, Erica decides to make a promesa to God in exchange for her mom's health. As her mom gets sicker, Erica quickly learns that juggling family, friends, school, and fulfilling a promesa is stressful, but with a little bit of hope and a lot of love, she just might be able to figure it out.