With some concern that your sister might be confused or scared, you put the pendant back on, and ran to the alley.
What you found confused you even more. Where your body had been, stood your sister, Karen, dressed identically to your current form.
"What the hell is going on?" Karen asked, as she staggered backwards at the sight of her identical clone "Are you an alien, are you going to eat my brain and replace me? Please don't. I'm too young!"
"Karen," you said "I'm not going to hurt you. I'm your brother."
"Oh my god, you ate my brother, too?"
"No!" you said "I am your brother, alright? Something weird happened when I came through this alley. I was given this pendant in exchange for an act of kindness, and it did this to me. Switched our positions, and changed me into this."
Karen took a few deep breaths, before she cautiously approaches you. She pokes you in the boob, which hurts alot more than you thought it would, as you scrambled backwards.
"John? Is that you?"
"Yeah," you said, the relief showing on your face "So you do believe me."
"Well, and I can't believe I'm saying this, it makes more sense than my previous theory. Can we go home? I don't think I'm quite done processing this."