When a person who was killed right in front of Phoebe comes back from the dead to blame her, she becomes guilt-ridden and vulnerable, creating an opportunity for Zankou to steal the Book of Shadows. Meanwhile, Paige has a new charge who knows nothing about magic, and Piper and Leo attempt to plan Chris's first birthday party.

Billie jeopardizes the Charmed Ones' new lives when Agent Murphy spots her using her powers to save an innocent. Meanwhile, Phoebe's overnight trip with Dex comes to a surprising conclusion when Billie casts a spell to make her happy, a spell with unexpected consequences.

Paige learns the difficulties of dating a mortal when Henry becomes too involved in the magical world and is torn when another suitor arrives hoping to convince her to marry him so they can become the ultimate magical couple. Meanwhile, Billie finally finds her missing sister, Christy; Piper faces a romantic decision when she runs into an old flame and begins to wonder if she should move on with her life.