The latest craze is Gizmo collecting – not just any old gizmo but the ones from the Sweet Tweet cereal boxes. There are ten in all, from common green to rare gold, which is the one that everyone, including Henry, is looking for. When Peter manages to get hold of one, Henry naturally starts looking for ways to make it his own. Stealing and swapping won’t work but trickery does, until Mum finds out, that is. But Henry’s still got one trick left up his sleeve.