"Dah you goes, de ole true Huck; de on'y white genlman dat ever kep' his promise to ole Jim" (16.16)
Oops. Well, gee. Now Huck can't tell on Jim, because Jim has made him feel super guilty—and also pointed out to us that, despite all the lies, Huck is probably the most moral person in the entire novel. Or maybe even in the entire pre-Civil War South.