Allie Pennington (Britt Robertson) is transferred to a new school (Avalon High) where she discovers that her new classmates are reincarnations of King Arthur and his court. Now her mission is to solve the school s mystery before Mordred wins again. Allie also meets the high school football quarterback, Will Wagner (Gregg Sulkin). Allie believes that Will is King Arthur and that a mean classmate Marco is Mordred, but it turns out that Marco is another Knight while Mr. Moore, one of her teachers is Mordred. It s revealed that Allie herself is King Arthur when she draws a plastic sword and it turns into Excalibur. Allie and her friends battle Mordred and after Miles (Merlin reincarnated) summons Merlin s staff away from Mordred, Allie defeats him. Mordred tries to have her arrested in the real world, but she turns Excalibur back into a plastic sword and Mordred/Mr. Moore is taken away as the police think he s insane.