Good conquers evil and all is right with the world.
That about sums up the ending of The King's Stilts, which comes to a sweeping close in spectacular children's book fashion. We see the villain, Lord Droon, duly punished as he is holed up into a measles-labeled house and forced to eat Nizzards for the rest of his life. We assume that Nizzards probably don't taste like chicken if this is supposed to be some kind of a terrible punishment.
Plus, we've got the triumph of honesty over deceit at the end, with Eric's truth-telling ways allowing him to find the King, and save Binn. Lord Droon, of course, is caught in his malicious web of lies, and, well, you know what happens next.
But more than anything, the ending reiterates the book's belief that balance is the cat's meow. The natural balance between humans and nature (see more of that in the "Themes" section) is restored when the Dike Trees are back in business holding back that pesky sea. The King and Eric's lives are balanced because they work hard every day and play hard every afternoon—like they used to.
And when the natural order of everything has been restored, peace (and happiness) reigns once more. Oh, and so does King Birtram, natch.