You give Rebecca a suspicious look. She usually never believes you when you tell her something weird or cool you've experienced, even when it truly happened, so why does she believe you now just right away? Rebecca notices than you're stunned by this and looks at you with a smirk on her face.
"Who do you think gave you this power?" Rebecca suddenly says and chuckles.
"Wait, you mean..."
"You didn't recognize my voice?" she asks, followed by a short giggle.
"Eh... well..." you stammer. Now that you think about it, remembering the voice that told you about your power, it indeed did sound like Rebecca, but it had a twist. Like Rebecca's voice with a sub-bass or something. It sounded like Rebecca's normal voice plus her voice an octave lower, together at the same time. That's why you didn't immediately recognize it as Rebecca's voice. But then, HOW THE F**K did she give you this power... and WHY ???
"Yesterday, I found an old book with a few magic spells," Rebecca starts explaining.
"There was a spell to detached and reattach body parts," she grabs her left hand and just pulls it off, "you see?"
With amazement you look at her detached hand and her stump. The stump is covered with normal looking skin, like she'd never had a hand on that arm. You take the hand from her and inspect it. The side that was attached to her arm is now covered with just plain looking skin as well. You tickle the palm, but the hand doesn't react.
"It's too bad I can't feel or control it now," she says, "there's another spell keeps the feeling and control when detaching something, but I can't read it. The book is too old."
Then she grabs her detached hand back from you and pushes it to her stump. It fuses back on. She wiggles her fingers and continues her story, "Anyway, there was another spell, which I could still read, to give someone the power to swap people's body parts."
"You didn't give this power to yourself?"
"I tried," she says, "but it didn't work. I figured that I can use the spell only to give someone else the power, so I tried it on you. I hope you don't mind."
"No, I don't mind," you reply with a smile on your face. "But next time you try a spell on me, could you ask me first?" you add and laugh.
"I will," she says and laughs as well.
"But why did you test it me?" you ask, "You trust me with this power?"
"Not really," she says and giggles, "but I know I can fix things that you messed up, if necessary."
You both laugh.
"Like Stella," she explains, "we can't let her go to school if she's got Catherine's boobs. So if you're not around to swap them back in time, I can take her nipples from Catherine, detach Catherine's boobs from her chest and then put her nipples back where they belong."
"And you give Catherine her boobs back," you add.
"Maybe," Rebecca says with a smirk on her face again, "maybe not."
You chuckle on the thought of Rebecca keeping Catherine's detached boobs for herself.
"Now show me your power," Rebecca says with some excitement in her voice, "swap something with me."