What does Huck tell the duke when he sees him the next day?

When the duke questions him, Huck concocts a story about how he wandered the town but found neither Jim nor the raft. The duke initially slips and reveals where Jim really is (on the Phelps farm) but then changes his story and says he sold Jim to a man forty miles away. The duke encourages Huck to head out on the three-day, forty-mile trip.