Max has promised his dad he is going to be a better monster. From now on he will only 'Protect and Do Good Stuff'! However, turning over a new leaf isn't easy. His arch enemy, Peregrine (and his devilishly amazing inventions), are doing his best to catch Max and throw him and his mum in a zoo. On top of this, something is causing a lot of damage in their quiet, leafy suburb and it isn't Max.
Can Max catch the real villain before Peregrine catches him?