Harold and Zelda sat in the engineer's compartment as the freight train picked up speed. "You know the trolley problem, Zee?" Harold had that smug, superior smile that she hated. "No, Harold." She rolled her eyes and stared out the window.

"It's this ethical problem. There are five people on the track ahead of you. You can save them by switching onto another track, but there's one person trapped there. So do you do nothing and let five die, or make a choice and kill one?"

Zelda sighed. "I dunno. I guess I switch the track."

"What if the lone person is a mother of five?"

"How would I know that?"

"I'm telling you." Harold's grin became, if possible, more unpleasant. "Mother of five and a part-time legal clerk. The rest are all stockbrokers. Whatcha gonna choose?"

"What the..." Zelda squinted at the figures tied to the rails ahead. When she looked back, Harold had a gun.

"Time to make an ethical decision, Zee. Clock's ticking."

Without any sudden moves, Zelda took the controls. The train jerked backward, throwing Harold to the ground. "It's called the emergency brake. It's for emergencies, jerkass." Taking the gun, she radioed for the police.