The boat ride is rocky and scary at first. Finally, the current slows, and they continue to pass along the river, in pitch-dark.
When the water's more calm, Doon lights a candle, and they see that they're in a high-ceilinged cavern.
Then the current picks up again, and they try to use the paddles to direct the boat. After a while, they reach a pool where there's no current at all, and the river doesn't seem to continue on anywhere.
The two bigger kids wade ashore, where they find a path. When Poppy is brought ashore, she finds something—a packet wrapped in some weird material. It turns out to be a book.
They sit down to eat some of Doon's food, and talk about what happened in their rush to escape. Lina realizes that she'd forgotten to give the note explaining the exit route to Clary—doh.
But there's nothing they can do about it now, so they decide to follow the path.