You’re ten years old. You’re at your best friend’s birthday party, a sleepover this year: An important rite of passage for any child. Even though you were all instructed by the parental units to go to bed no later than ten o’clock, you’ve stayed awake for hours afterwards, tucked into your sleeping bags and laughing with another in the dark. Out of the sea of pillows drifts a solitary whisper: “Let’s play Bloody Mary!” A…