For the next few weeks, Arthur stays busy helping everyone with cleaning and repairing things around town and underground.
The court date against Snatcher and his minions arrives, but they don't show up, so the court awards Herbert and Grandfather the property that the Cheese Hall once stood on.
Now it's a giant hole filled with water, so they get the idea to turn it into a swimming pool and charge admission; the pirates act as lifeguards and everyone's happy with the deal.
At some point, a Parisian lady arrives in town, and the fashionable Ratbridge ladies ask her if oddly-shaped buttocks are in fashion. The lady responds with horror.
The Ratbridge ladies eventually storm the ship, demanding to have their buttocks resized with the resizing machine they've heard of. Marjorie agrees, and charges them money plus their mini-critters they've been keeping as pets.
So they're able to resize the underlings that were shrunk, and Marjorie, too, all while turning a profit. Once all the resizing is done, Willbury has Herbert destroy the resizer to prevent it from being used for evil again.
Marjorie decides to go into another area of invention, one that's less dangerous, and Arthur asks to be her assistant.
They have a party on the ship to celebrate. Grandfather, Arthur, and Willbury all agree that even though Ratbridge is weird, they like it there.