Ironically, even though the king and the duke have taken gross advantage of Huck and Jim in The Adventures of Huckleberry Finn by Mark Twain, and even in light of the fact that they are criminals, Huck demonstrates again what a good person he is: he feels somehow to blame for the circumstances in which the con-men find themselves, worrying for their safety.
Because Jim was sold back into slavery by the king, Jim decides to get his revenge: he exacts justice from the crooks when Jim exposes that the king and the duke are frauds. Huck, feeling bad about it all, goes with Tom Sawyer to warn the men.
...we bid good night and went up to bed right after supper, and clumb out of the window and down the lightning rode, and shoved for the town; for I didn't believe anybody was going to give the king and the duke a hint, and so if I didn't hurry up and give them one, they get into trouble sure.
As Tom and Huck walk, they catch up on what has happened since Huck staged his murder. However, as they come closer to town, Huck realizes they are too late: there is a crowd raging past them—they have the king and the duke, tarred and feathered, and are running them out of town.
...I see they had the king and the duke astraddle of a rail—that is, I knowed it was the king and the duke, though they was all over tar and feathers, and didn't look like nothing in the world that was human...Well, it made me sick to see it; and I was sorry for them poor pitiful rascals...
After the crowd has passed, Huck asks a few people who linger behind what happened. After he hears the details, Huck says:
...I warn't feeling so brash as I was before, but kind of ornery, and humble, and to blame, somehow—though I hadn't done nothing.
This sadness is similar to what Huck felt when he was living with the Grangerfords earlier in the story. When Huck's friend Buck is killed, Huck is devastated by the harsh reality of life away from the river, and the loss of life. Again, as before, Huck finds himself in a world he does not understand when he lives on land rather than traveling down the river.