The Charmed Ones skulk through Magic School, where they have found evil. Piper thinks the evil is Billie and Christy. They find a door and behind it is a dark room with a glowing white table inside. The room is creepy and the sisters leave. Demons shimmer in and one raises a fireball, but Christy stops them. She confronts the Charmed Ones, who orb out.
The Charmed Ones want to enlist the aid of other magical beings to identify the evil at Magic School. Paige goes to three leprechauns and asks for their help. The leprechauns are reluctant, but Paige suggests she might ask the gnomes. This wounds the leprechauns' pride and they agree to help.
Coop transports to Phoebe and she almost blasts him with a potion. He says he can set her up with an aid worker in Bangladesh. Phoebe tells Coop that he in fact is the man she wants, they kiss as Piper walks in.
Billie and Christy enter the dark room. Billie is still reluctant to kill the Charmed Ones, but Christy tries to tell her that the Charmed Ones have lost their way. To help convince Billie, the demon Dumain appears. He apparently was an imaginary friend of Christy. He shows them the scene of future evil Wyatt confronting Chris ("Chris-Crossed"). Dumain tells the Jenkinses that if the Charmed Ones' power remains unchecked, it will eventually corrupt them, resulting in Wyatt turning evil. Therefore, Dumain says, it is Billie and Christy's destiny to stop Wyatt by taking out the Charmed Ones. Billie is still reluctant. The Jenkinses leave, and the ghostly forms of the Triad appear to Dumain. The Triad has been planning for some time to use Billie and Christy to wipe out the Charmed Ones, with Dumain's encouragement. The Triad plans to return when the Charmed Ones are killed. They plan to make Dumain one of them as a reward.
The Triad vanishes and Dumain walks away as two leprechauns walk in. One produces a disposable camera as the other says an incantation. A magical wind chases them away. Dumain walks back in, and at the order of the Triad, summons Creo.
Demons attack the Jenkinses as the leprechauns duck for cover. Billie and Christy fight them off and befriend the leprechauns. One of them expresses disgust at being used as "cannon fodder" for the Charmed Ones. Paige and Phoebe orb to the two demons. Paige throws them against a dumpster and Phoebe throws a truth potion. The demons vanquish each other rather than talk.
Paige reaches for the shillelagh that Riley gave her in "Spin City" and calls for the leprechauns. They are angry and one of them takes the shillelagh away. The two rainbow away.
Dumain meets the Triad again and tells them his plan to isolate the Charmed Ones. Earlier, Billie was seen writing down all the Charmed Ones' weaknesses in a diary, and Dumain plans to use it to ruin the Charmed Ones' reputations with the magical community. Paige goes to the leprechauns and tries to reason with them. Just as she's trying to warn them, Dumain casts a spell and now Paige only wants "enlightenment." She orbs away from the astonished leprechauns. Phoebe goes to Coop to try to keep him on the Charmed Ones' side. Dumain's spell fills her with desire for him and they kiss. Piper is flipping through the Book of Shadows when Dumain conjures Grams's Ring onto her finger. She morphs into the stereotypical housewife, and becomes obsessed with cleaning the manor.
The leprechauns have gathered a meeting of magical creatures. The leprechauns don't believe in the Charmed Ones anymore, but the others are skeptical. Demons attack and the beings try to summon the Charmed Ones; but Paige is gazing at her navel and orbs a leprechaun into the bay, Phoebe is getting horizontal with Coop and Piper is too busy baking and vacuuming to respond. The respective spells break, but it's too late. The leprechaun goes to Billie and Christy, not knowing that they and their "friend" Dumain was behind it all. Billie and Christy "save" the magical beings, who then turn on the Charmed Ones. Christy conjures a huge fireball, and Billie telekinetically sends it at the Charmed Ones. However, the Charmed Ones grab the Book and orb away. They find themselves in the underworld, having been repelled from Magic School.
Dumain meets the Triad again and tells them of the coming battle -- which will destroy Billie and Christy as well as the Charmed Ones.