Merry leads his pony to the Ferry and they all cross the river.
On the eastern side of the Brandywine River lies Brandy Hall, the ancient home of the Brandybuck family. Brandy Hall is a giant network of tunnels, and the people who live in it (the Bucklanders) practically form their own country under the authority of the Master of the Hall (the head of the Brandybuck family).
In some ways, the Bucklanders are quite different from the people of the old Shire: they like swimming in the Brandywine River, and they also keep their doors locked after dark, since their home is less naturally protected from the rest of the world.
As Merry ties up the ferry-boat, Sam points to something on the Hobbiton side of the river: it's a dark shape crawling along the bank.
Frodo pulls the other Hobbits away, glad that there are no boats kept on that side of the river.
They go to Frodo's new house in Crickhollow, somewhat far from Brandy Hall.
Fatty Bolger opens the door, and Frodo is impressed at how homelike it seems: Fatty and Merry have already settled much of Frodo's furniture.
Frodo knows he has to tell his cousins that he's not planning on staying.
But first things first, they all have a hot bath and some supper.
Over dinner, Sam and Pippin start telling Merry about the Black Riders.
Frodo doesn't want to say anything too definite, but he does admit that the Black Riders are looking for him, and that it's not safe for him to stay in the Shire.
Merry sees how miserable Frodo looks and finally tells him that they all know he's leaving the Shire: he's been totally obvious about it. Subtlety is not his strong suit.
In fact, ever since Bilbo left, Merry has been waiting for Frodo to follow him.
What's more, Merry, Pippin, and Fatty all know about the Ring.
Merry found out when Bilbo was still in the Shire: one day, a year before Bilbo's disappearance, he watched Bilbo disappear into thin air to avoid the Sackville-Bagginses.
Merry had been hiding behind a hedge, and he was looking right at Bilbo when he suddenly reappeared, catching "a glint of gold as he put something back in his trouser-pocket" (1.5.62).
Merry didn't say a word to anyone until he discovered that the Ring was a danger.
Most of Merry's information has come from none other than Sam Gamgee, who has been spying on behalf of Frodo's friends.
Frodo is shocked, but he has to admit that he's relieved: Gildor told him to find companions, and now here they are, all ready to volunteer.
Merry assures Frodo that they are ready to leave whenever he likes, so Frodo decides to set out at dawn the next day.
He also doesn't want to take the main road; he wants to cut across the Old Forest.
Fatty Bolger points out that no one goes into the Old Forest, but Merry protests: Bucklanders do, sometimes, and they have their own private entrance.
Fatty admits that he has no part in this decision; Fatty will stay at Crickhollow impersonating Frodo to try to keep Frodo's departure from the Shire hidden for as long as he can.