The liquid drained and the chamber opened. The girl in the machine coughed and said "How did I get in here? I was just outside starting up the machine. Wait, I'm a girl! What happened to me?"
From outside, Jon's mother yelled "How's that build-a-man kit working? I can't believe your grandfather sent you something so science fiction-ish."
Jon's grandfather? Yeah, that must have been it. The stone changed reality. So, what's the most logical explanation for Jon having an impossible device? Of course it was inheriting the device from his grandfather. He already had a magic stone and that wasn't any less impossible.
Jon opened his bedroom door and called out "It works great, Mom!"
"Maybe you could show me it later," she called back.
"Sure thing," Jon answered back. Then he closed his door and turned back towards Karyn and the female version of himself, who was currently checking out her body.
She looked up at Jon and said ...