Eleven-year-old Joey is angry. All the time. And she doesn’t understand why. She has two loving moms, a supportive older half brother, and, as a triplet, she’s never without company. Her life is good. But sometimes she loses her temper and lashes out, like the time she threw a soccer ball—hard—at a boy in gym class and bruised his collarbone. Or when jealousy made her push her (former) best friend (and crush), Layla, a little bit too roughly.

After a meltdown at Joey’s apartment building leads to her family’s eviction, Joey is desperate to figure out why she’s so mad. A new unit in science class makes her wonder if the reason is genetics. Does she lose control because of something she inherited from the donor her mothers chose?