He knows there is Dragon-Lord left and knows where to ... and even before you get to the Empire Strikes Back father/son moment, Balinor is worm food, and Merlin shows all the emotion of a plank ...

Finally free, the Great Dragon attacks Camelot ... Dragonlord is the key to Merlin's own past as well as the future of Camelot, but will Arthur and Merlin find Balinor in time to save the kingdom?