She commandeered the room in the basement of her dorm as soon as she realized she would have to pull an all-nighter in order to prepare for tomorrow’s final exam. Her roommate, Jenna, liked to get to bed early, so she packed up everything she thought she would need and went downstairs to study . . . and study . . . and study some more. She could hear Jenna breathing on the far side of the room—a heavy sound, almost as if she had been running. Jenna must have picked up a cold during the last tense week before finals.