David finds a canoe drifted down stream. After a misunderstanding he meets Adam, who now lives, with his grandparents, following the death of his father. Adam asks David to help find Jonathan Codling's treasure but needs to decode a rhyme.
Adam and David find a loose brick on the bridge but the treasure has long gone. David finds a clue but Adam's grandfather dies. The note says he had found the treasure but hid it again. Adam becomes suspicious his neighbours the Smith's.
David and Adam know the Squeak Wilson is an unwitting key to the treasure. David learns that the Smith's are also Codling descendants, the Ashworthy-Smith's. Smith buys the house and the treasure is in his grasp leaving the boys just days.