Oscar, Arabella, and their friends can't wait to begin their second term at the Mammoth Academy. But, when they arrive at school on the first day after winter break, there's a threatening graffiti message waiting for them. It seems the Cave Skool has moved nearby, and its pupils, those wild and dangerous animals called humans, are wreaking havoc. When a huge snowstorm hits and everyone is trapped inside the academy, the humans attack! With a little...