50.5 seconds and she would be safe... safe from the sight of the fat girl with the sad eyes. Bella didn't want to fight against the obnoxious impulse to save the girl from the sorrows that drove her to eat her feelings instead of dealing with them.
She didn't want to be reminded of a time when food was her only escape from the ugly reality of abuse and neglect. Bella didn't need to revive the pain of being bullied because of her weight. That's why she altered her schedule, choosing to leave the apartment five minutes ahead of time – she needed to avoid the fat girl at any cost.
However, luck wasn't on her side. The fat girl came into the elevator, and Bella was condemned to 36.9 seconds of hell.