Merlin: The Nightmare Begins

Out on a hunting trip, Arthur kills a unicorn. Merlin rushes to the animal's side, obviously upset, as the knights cheer Arthur for killing this most highly-prized of beasts. But, it seems that by killing the magical creature Arthur has cursed Camelot and until he makes amends for his actions the great city will be damned. Could this be the end of Camelot and her people?