Clover and Danny are the kind of best friends who make each other better: Clover makes lists, and Danny makes fun. Clover is good at science, and Danny is an artist. They’re so important to each other that Clover believes they’re symbiotic: her favorite science word that describes two beings who can’t function without the other.

But when Danny comes down with a mysterious illness, there’s no more balance in Clover’s world. Suddenly long days in the pool are replaced by long doctor’s visits, and no one-not even the doctors-can explain what’s making Danny so sick. So Clover decides to take matters into her own hands by turning to the scientific method.

Clover makes lists of Danny’s symptoms, his good days, his bad days, and his moods. As the evidence piles up, only one thing become clear: Danny is only better when Clover is around. When they’re separated, he’s in danger.

Clover knows that they need to find a cure-together. Will science be able to save Danny, or is this one time when hope and magic can overcome the unthinkable