The Charmed Ones are called upon by The Lady of the Lake to help protect Excalibur, the legendary Sword in the Stone. Meanwhile, numerous magical beings arrive at the manor to try their hand at pulling the sword from the stone, but it's Piper who finally pulls Excalibur out of the stone, causing a surprise figure to appear.

When Piper is kidnapped and cocooned by the Spider Demon, and becomes Chris infected with the Demon's venom, causing him to mutate into a spider, Paige, Phoebe and Leo try to rescue them. Meanwhile, Leo finally learns why Chris resents him.