when tillie and gus arrive in danville, they are mistaken for missionaries newly returned from africa by their relatives. tillie plans to sell the boat and split the profits, but they become suspicious when pratt expresses an inordinate interest in acquiring the seemingly unseaworthy boat, and they decide to help mary and tom refurbish it. pratt, who has just purchased his own boat, the "keystone," tries to eliminate the competition by convincing the state inspection board to deny the sheridans a ferry franchise.