"I'm a professor of Xenobiotics, not Parapsychology," the professor said snootily. "Even so, I can say with certainty that your story is completely fallacious.

"It is?" Dean said.

"The macrocosm of our universe is such that it would be impossible for the creatures you describe to exist."

"Yeah?"

She nodded, extremely satisfied with herself.

Two minutes later, Sam walked into the classroom and found Dean standing over the professor's dead body.

"Dean!"

"Chill, Sammy. I'm good."

"Was she a demon?

"Nope."

"Shapeshifter?"

"No."

"Djinn? Werewolf?"

"Nah." Dean wiped the blood-moist knife on his jeans. "She was just really fucking irritating."