Chris enters Piper's office at the club to find a beautiful young woman waiting for him. "Bianca," he says. "What are you doing here?"
She runs her hand along his chest, revealing a birthmark in the shape of a bird on her wrist. She plunges her fist into his chest, draining his powers. Piper enters and blows Bianca up. But in the alley outside the club, Bianca reforms.
The sisters try to identify Bianca in the Book of Shadows. Leo suspects that Chris knows more than he's letting on. He paces across the floor of the attic and a floorboard squeaks. He tells the sisters that if they can figure out who's after Chris, they may be able to figure out Chris's identity.
Meanwhile, in the bathroom, Chris opens his shirt to reveal a wound in his chest the size of a fist. He flashes back to a scene before he traveled back in time. He and Bianca meet secretly in a walled garden, and he proposes to her. A futuristic electronic device flies toward them. Using his power of telekinesis, Chris throws it against the wall, smashing it.
"I cannot believe he's sending probes after us now," Chris says. "I'm going to kill that son of a bitch!"
"No, you're not," Bianca says. "You're going to stick to the plan…You have to go back, Chris. It's the only way to stop them. It's the only way to change all this."
Leo discovers that Bianca is part of a coven of assassin witches called the Phoenix. He tells the sisters that if there's a bounty out on Chris, the coven will keep coming after him.
Across town, Piper and Paige knock on the door of an apartment, telling the woman who answers that they're her new neighbors. She invites them in, but she's suspicious. A little girl runs in, whom the woman calls Bianca. Piper and Paige notice the Phoenix birthmark on the girl's wrist.
The little girl goes to her room, and the mother throws an energy ball at Piper and Paige. Piper blows the woman up. The sisters go to the little girl's bedroom, where the mother reforms. She grabs little Bianca's arm and shimmers out. The sisters realize that if the mother can reform, Bianca can, too.
Meanwhile, at the Bay Mirror, Elise offers Phoebe the opportunity to go live in Hong Kong with Jason. Phoebe is reluctant, but Elise says, "Trust me, you don't want to wake up one day and realize that all you've got is your career."
Chris goes to the same park where he proposed to Bianca and finds her waiting for him. "You really shouldn't try to orb anymore," Bianca says. "It could kill you…I was interrupted in stripping you of your powers. And if I don't finish what I started, you'll die soon." But Chris orbs out before she can get to him.
Back at the manor, Chris collapses, weak from orbing. The sisters discover the wound in his chest and Leo tries unsuccessfully to heal him. Phoebe finds Bianca's engagement ring in Chris's hand. They use it to scry for Bianca, making a vanquishing potion in case she's uncooperative.
Chris, unconscious, remembers the day he traveled back to the past. He and Bianca enter the manor, now a museum. They hide in the basement until closing time. Then, they go to the attic. While Bianca draws a triquetra on the wall, Chris says a spell to summon the Book of Shadows. Chris finds a spell in the Book to transport him back in time. As the triquetra on the wall turns into a portal, Bianca gives him her engagement ring to remind him of what he has to come back to, once he's saved Wyatt from evil. Chris walks through the portal, into the past.
Adult Bianca goes to her mother's apartment to find her family's grimoire. She locates the inhibition spell, which she plans to use to distract the Charmed Ones long enough for her to take Chris back home to the future. As the sisters prepare to go after Bianca, a blue light suddenly washes over them. Paige announces that she's moving in with Richard, her boyfriend, and Phoebe says that she's moving to Hong Kong with Jason. Piper dresses for her date with Greg the fireman. Leo realizes that they're under a spell, but he can't turn their attention back to Chris. The sisters go their separate ways, and Bianca shimmers in, taking hold of Chris and shimmering out with him.
At her mother's apartment, Bianca finishes draining Chris of his powers. She draws a triquetra on the wall. "You don't have to believe me, Chris," she says, "but this really is for the best…If I fail, he'll just keep sending more assassins back, and all they'll bring home is a body."
Leo uses a potion to reverse the spell on the sisters. They orb to the apartment. Piper throws the vanquishing potion at Bianca, but she shimmers out. She reappears holding a knife to Piper's throat. Chris tells Bianca that if she releases Piper, he'll go to the future with her. Bianca drops the knife and walks toward the portal with Chris. Piper tries to freeze them but can't. The sisters realize that if Chris didn't freeze, that means he's also a witch. As he steps into the portal, Chris says to the sisters, "Looks like Leo's going to have to fix that floorboard without me."
On the other side of the portal, a man is in the attic of the manor waiting. "Welcome home, Chris."
Chris looks at him in disgust. "Hello, Wyatt."
Meanwhile, the sisters orb back to the manor and go to the attic to look through the Book. While they try to find a way to travel forward in time to get Chris, Leo paces, and the floorboard squeaks again. The sisters realize that Chris was sending them a message. They write a spell for Chris to get his powers back and place it under the floorboard.
Meanwhile, in the future, Wyatt says to Chris, "You know if anyone else tried what you tried, I'd kill them on the spot. But you…I've forgiven Bianca, I can forgive you too. If you promise never to cross me again."
Chris looks at him defiantly. "I think you know me better than that."
Wyatt uses his telekinesis to send Chris flying across the room. Wyatt approaches him, stepping on the squeaky floor board. Chris lunges toward him, knocking him down.
"Chris, please," Bianca cries, "I didn't bring you here to die."
"Don't worry, I know what I'm doing," Chris says.
Wyatt generates an energy ball. Bianca reaches into Wyatt's back. "Whatever you're going to do," she says to Chris, "do it fast. I can't hold him for long."
Chris lifts up the loose floorboard and takes out the spell. He recites it, and a blue light shines over him. His powers return. Wyatt breaks free from Bianca's grip. He turns and throws her toward the wall. She's impaled on a broken table leg. Chris rushes to her. He knows that he can't save her, but realizes that if he changes the future, he can prevent her death. Taking along the spell that Wyatt used to send Bianca after him, Chris goes back through the portal.
In the attic with the sisters, Chris says, "I'm sorry I lied to you. I really am, but-"
"No buts," Piper says. "It's about time you tell us the truth."
"I can't," Chris says. "There's only so much I can tell you without the future being changed too much."
"Isn't that your whole point?" Paige asks. "To come and change the future?"
"Yeah," Chris says, "but that was supposed to be more like a surgical strike."
"To save Wyatt," Leo says.
"To save Wyatt," Chris replies. He goes downstairs and walks by Piper's room, where Wyatt is in the playpen. "If I can't save you," Chris says, "I swear to God I'll stop you."
Later, Piper meets with her sisters and they talk about what happened while they were under the inhibition spell. Piper suggests that Paige move in with Richard, and Phoebe with Jason. "You can't keep sacrificing your lives forever," Piper says, "and neither can I. Mom did that, Grams did it, and even Prue. And look what happened to them. It's not a legacy I want us to inherit."
"What if it doesn't work out," Paige asks, "us going our separate ways?"
"Well," Piper says, "we'll worry about it then."