When Minnie finds a huge dragon hiding in a cave, starving to death, she knows that, terrifying though he is, she has to do everything she can to keep him alive. He needs food and lots of it. He says he's a vegetarian but his teeth are very sharp. Is he telling her the truth? At first it doesn't matter; he's too weak to eat anyone, but what will happen when he gets his strength back?

It's not easy finding enough food for an enormous dragon, not when the bullies at school take her pocket money every week. No-one can help Minnie either, because she's promised not to tell anyone in case they put him in a cage. But Minnie isn't the only one with a secret. The dragon has a secret too, and Minnie must find out what this secret is. It's the only way to save his life.