Mark scratched his head and wondered how to proceed. As he did so, his older sister Jennifer walked by his open bedroom door and continued down the hall to the bathroom. She had recently turned 18, though she was still a senior in high school while Mark was just a sophomore. He knew she'd be in the bathroom forever, primping and preening trying to look her best. Jennifer was a nice enough person – she was just vain and a bit of an airhead, devoting all her time to fashion, make-up, and boys.
“Jennifer, you just became the perfect test subject,” Mark whispered to himself.
He crept quietly down the hall, pushed the already ajar bathroom door open just a smidge wider, aimed the device at Jennifer and pushed a button.