There's a canal that runs through Ratbridge, and this is where the ship that Tom and Kipper call home is located. It looks suspiciously like a pirate ship.
Marjorie identifies a beam engine on the ship, which is apparently a big deal since it's a pretty impressive machine; Tom and Kipper won't say much about where they got it, though.
As they board the ship, a bunch of crows complain about the rain and how it's keeping the latest load of clothes from drying.
On the way to find the captain, Tom explains to Arthur how their laundry business works. Crows, humans, and rats all work together to clean and sort everything. It seems kind of like a collective.
When they meet the captain (a rat wearing a big hat), Tom explains that they're also dealing with disappearances.
Apparently Framley (who was lazy and mean and disliked) disappeared about a week ago, and a little after that, the other two rats, Levi and Pickles, never came back from a shopping trip.
Something else weird happened: An unpleasant dude named Snatcher visited the ship and invited the humans to join his guild.
He sounded like he hated rats, though, so they didn't get along.
Framley and Snatcher had a conversation before Snatcher left, though, and one of his dudes was named Gristle—probably the same guy who came to the pet shop that morning selling mini critters.
The captain calls in another rat, named Bert, who describes how the Cheese Hall (which Snatcher mentioned) is not deserted like it's supposed to be, and instead there are noises and lights coming from within it.
They decide to leave the mini critters on the ship to go investigate. Willbury will knock on the front door of the Cheese Hall, while everyone hides out and watches from the inn across the street. Sounds like a plan, and go team.