Tabitha-no-last-name, young vampiress and precognitive magic child, was bored. That is, she was bored until she considered breaking into the museum after it closed. It was then she realised she wasn't getting any possible futures for that choice. This intrigued her enough to go. Her twin brother wasn't able to talk her out of it, and so decided to tag along. Now they're climbing all over the tyrannosaurus display.
A phone booth appears next to the dinosaur.
A man steps out and glances up at them.
"You've seen nothing. I'm not real," he says, continuing deeper into the museum.
"Neither do we," says the girl child, hopping down from the skeleton.
"If you follow me, you'll die," he says, not slowing his pace.
Her brother follows. "Hello, mister." He sniffs. "Are you a person? 'Cause you don't smell like a human or a vampire, and I'm pretty sure you did a magic thing." He isn't bothering with the pretense of humanity this time. Which is a shame, they brought pants and everything just in case a night guard or something found them.
"I'm a demon. I make little children disintegrate."
"Ooh, are you one of Lilith's children, too?"
"Do you even know what that means?"
He glances over his shoulder and grins at her, "Nope!"
He stops and spins around.
"Now how did you do that?"
She resumes humanish form, picking up her clothes. It might occur to the man that the two children are very, very pale. "Vampire magic."
"Can you do anything else?"
"We're better than humans at most things, and me and Tabby are witches. She sees the future, I see the past."
The Master kneels down in front of Tabitha and grabs her shoulders, staring into her eyes.
"Are you being magic?"
"Can you see my future?"
She tries. All she gets is static. "Too many."
He turns to the boy.
"Can you see my past?"
"I need to touch you."
The Master holds out a hand.
"Come on, try it."
He does so. He jerks his hand away almost immediately. "Your past gets really hard to look at before you got here. And are you an alien?"
"I am and you are more interesting than a cursed crown."
"Oh, so that's why you don't smell yummy."