Piper is making arrangements to get a band into the club without much luck while Leo is preparing to play golf with a booker. Phoebe shows up and reveals Agent Murphy wants them to go through old case files for him and that she's busy looking for love.
Piper and Phoebe go to the warehouse filled with files but Piper quickly slips out to meet with the booker, leaving Phoebe on her own. At the Magic School, another demon, Zira, wants a route to power when she's interrupted by the head demon, Ti, who wants to know how the potion-making is going. Zira isn't happy and plans to eliminate all male demons. In Billie is attending a lecture about the battle of the sexes and is dubious about the teacher's assertion the sexes need each other.
Piper is meeting with the booker, Smitty, about her inability to get bands in, and the guy offers to get a "chick band" in, and Piper isn't happy with his dismissive attitude or that Leo is playing along with it. Paige is in an alley trying to meet with her new charge, Speed, who is a street punk at a crossroad. She sees him get grabbed by another guy and interrupts – Speed isn't too happy with her help. Then a parole officer shows up and arrests him for consorting with a known felon. Phoebe ropes in Billie to help her and Billie finds a belt that she puts on, transforming her into a new superhero-like outfit.
Phoebe warns there's not much they can do about it and they catch a taxi, where Billie discovers she has super-strength. Zira's assistant picks up that the belt, the Golden Belt of Gaea, has been activated and that she wants it, but it only works on those of good. Zira plans to manipulate Billie since the belt forces its wearer to use its powers. Paige confronts the parole officer, Henry Mitchell, and invokes Homeland Security to get speed released.
Leo and Piper are fighting over Smitty when Billie barges in with her newfound super-strength and the ability to render men invisible, starting with Leo. Billie starts to get angrier and they head for the book, while an invisible Leo reveals the belt will drive its wearer insane. Zira takes Ti to find the belt by convincing him to torment a woman to attract Billie. Billie is getting increasingly angry then superspeeds off as she "gets a call." Ti and his assistants are tormenting a woman when Billie shows up and deflects his energy blasts. She zaps him in the shoulder and he teleports out.
The next morning Billie superspeeds back to the Manor and refuses to take the belt off. Worse, it becomes clear that the belt is affecting Piper and Phoebe as well, while Billie heads off to her mid-terms after restoring Leo to visibility. Zira is trying to hold Ti off and is unhappy Billie isn't with her yet, but the male demon she's working with advises caution. Paige is at Speed's apartment when Henry shows up and wonders why he's so skeptical about Speed. Henry reveals Speed's friend Donnie has talked him into robbing a liquor store, and he'll take Paige along to show her.
At the mid-term, Billie shows up "in costume" halfway through and the women start attacking the men. Billie heads outside and Zira is there to offer her assistance. Leo reveals the background on the belt and that if it's combined with Billie's combined powers she could kill all men. Zira works to undermine Billie and it becomes clear Billie will soon die, but Zira is fine with that as long as Ti ends up dead.
Paige is with Henry on stakeout at the liquor store, while Donnie forces Speed to participate in the robbery as the driver. Speed ducks out and Donnie stabs him as he goes, while the police show up to arrest the two in the store, and Paige and Henry thinks he fled the crime.
Piper and Phoebe use a spell to summon Billie to the Manor attic and she isn't thrilled when she arrives. They imprison her in a crystal circle but Billie blasts her way free in a fit of rage and then superspeeds off to return to Zira to offer her full assistance.
Leo returns and figures that one of the books at Magic School might hold the answer. Meanwhile, Speed gets back to his apartment where Henry and Paige are waiting for him. They see Speed is wounded and Paige convinces Henry to check out Speed's story. Then Paige gets a call from the others, while Zira and Billie confront Ti and Billie destroys him as well as Zira's henchman. Leo sneaks in invisibly to go through the books while Billie begins to weaken from the effects. The three Halliwells confront Billie while Leo finds the book with the spell. Leo attacks Billie while Paige orbs the book to her and casts the spell. She gets the belt and orbs it onto Zira, destroying her. They restore Leo to visibility while they tell Billie what happened.
Walker checks up on Donnie and confirms Speed's story, then releases him. He calls up Paige and apologies, while at P3 Liz Phair is performing to a full house