One day while Sonic is waiting for a potentially stressful encounter with Amy, he is abruptly summoned into the book of King Arthur and the Knights of the Round Table by a frantic sorceress called Merlina. The young sorceress is being hunted down by King Arthur himself and begs Sonic to heelp her save the fabled kingdom.
Our little blue hero immediately finds himself slap bang in the middle of the action where he is greeted by a less than noble looking king. The once beloved monarch is now bewitched by the power of the mighty Excalibur's scabbard, and as the Black Knight, he is spreading terror throughout Camelot. To defeat the evil king, Sonic teams up with Caliburn, a sacred sword with a proud manner. Sonic must learn to properly handle the blade as an honourable knight and prove he is worthy of challenging the great king. Meeting familiar faces along the way, Sonic must defeat the evil Arthur and ultimately find a way to restore Camelot.