An intellegent boy figures he would make another human into his personal pet. It would be easy enough for him to gag her to keep her quiet while his parents were around. When they leave the house, he would take her out of his hiding place and do a little training. He captures and chains up a girl whom he's been targeted inside his mansion.
It's the weekend, so the missing reports won't be going out yet, but her sister is worried, while he's trying to crack her.
Perhaps her sister makes a sort of ruckus, and he tells her that she either needs to deal with it, or he's going to kill her. She thinks he's bluffing, so he decides to murder one of her friends to show that he's not. [This part is optional.]
Suggestions/Idea's are fine! Looking for a female who can consistently post 3+ paragraphs and is on pretty often.