The Secret of the Swamp King (Wilderking Trilogy)

No one has ever come home from the Feechiefen Swamp. What makes Aidan think he can?

It looks like a fool's errand. A jealous and vindictive King Darrow sends Aidan Errolson on a seemingly impossible quest into the depths of the Feechiefen Swamp. Darrow thinks he's sending Corenwald's young deliverer to certain death. No one, after all, comes back from the Feechiefen. He doesn't know that Aidan has friends and allies among the feechiefolk, who know him as the hero Pantherbane.

But even the feechiefolk may not be able to deliver Aidan from the enemy who waits in the swamp's deepest recesses an enemy who threatens not just Aidan, but all of Corenwald.