After escaping the Howling Tower with Mops, Benjamin is determined to find out where his parents are. But the two friends are unable to avoidcapture again, and after witnessing the cruelty of the gallow-boat, where he finds his father as one of the saps used to power it, they are taken to be pet-saps by King Antonius and Queen Dearie. When Benjamin rebels violently against the Queen's cruel attempts at obedience training, Benjamin finds himself facing a worse horror than he ever could have imagined...What will be the future for him and Mops?