Small Bites Back by Hannah Moffat & Rory Walker

In Small! Harvey went to a school for giants- but now we follow Harvey and his friend Walloping Toenail into the Vampire mountains as they try to work out what made the Never-Ending Contracts never-ending and tied Norma Enormous and the Skelephant to the Unspeakable Circus. Something's bitten the contracts. Could it be something with never-ending venom?