[Originally posted at Ana Mardoll's Ramblings.]
The bedridden king and non-jerk have a nice conversation where non-jerk makes it clear that he has no idea if he is long lost prince and king dispenses his general principles on rulership (general because he's not planning on going into too much nitty gritty detail on the first meeting.)
Then the king speaks privately with the mage where he asks if the mage was unable to find his son and who the Hell was that? At first the mage lies but then the king points out that real-son had a birthmark/scar/[thing used to identify the lost heir] which non-jerk clearly lacks. Mage delivers the unpleasant news that king's son, the jerk, is utterly unfit for rule. He then claims that non-jerk, who is in fact the son of the head of the stables and one of the king's seamstresses (they were killed in the same attack that was thought to have killed the prince) is a perfect fit.
King is convinced, over time, that this is a wise decision and claims the stable-seamstress-son as his own before he dies, passing off rule to the commoner. The jerk who is the rightful prince is well taken care of, but he never gets over the fact that his adopted brother (whom he is sure he is better than) turned out to be royalty.
* "Thing" here means, "Not a story, more of an ending with only the vaguest ideas of a story leading up to it," but that seemed too long to stick in the line.