Nina and the Chem Lab Catastrophe — Rebel Girls

In book two, Nina and her friends realize they can use the magical mailbox to help their fellow students deal with their problems. Soon there’s a stream of kids looking for advice.Not wanting to divulge their secret to other students, they say that they merely draw on history to give their advice. But when a student takes the advice from a letter Marie Curie sent a little too literally, almost blowing up the science wing, their operation is forced underground. What's worse, a new principal arrives on a mission to improve standards, and he seems to know a little more about Ada Lovelace Middle School than he's letting on . . .