Scarred-A Gravity Falls Fanfic

The Trap

Dipper swam in an infinite nothingness. Well, not really. There were random objects floating about, and Dipper could see an end. There were windows in random places, even on the supposed floor. He saw a figure hunched in a corner.
"Are you Madeline... Or M?" He asked hesitantly.
"Both. M is Madeline, Madeline is M." The figure turned around, and she looked just like M. "I prefer the name Madeline, though." She giggled.
"We need to get you out of here, come on." Dipper pointed to the exit... Which was no longer there.
"No, not until he activates the machine. We wait. Then the portal will open."
"Yeah, okay." Dipper stared closely at the figure.
"You... You aren't M. Or Madeline." He said, a little unsure.
"Whatever makes you think that?" Whoever she was asked, with a hurt look on your face.
"Because she... She wouldn't have stayed in here calmly, she would... She would have already found a way to escape, not just sit around!" He exclaims. The figure grinned, and her teeth turned razor sharp.
"Well, I'm not really sure about your reasoning... But you got the first half right!" The figure morphed into a beast with red eyes and yellow fangs twisted into a devious grin, and lunged at Dipper, aiming at his throat.