Huck finds the Duke - what story does Huck tell him about the raft?

Huck asks the Duke what happened to the raft and the Duke replies:

“Blamed if I know—that is, what’s become of the raft. That old fool had made a trade and got forty dollars, and when we found him in the doggery the loafers had matched half-dollars with him and got every cent but what he’d spent for whisky; and when I got him home late last night and found the raft gone, we said, ’That little rascal has stole our raft and shook us, and run off down the river.’”