" I told her the truth—a version of it. A portion, calved off from the whole. I was an agent of the Underground Airlines. I was going down into the Four to recover something that had been lost, a weapon in the battle against the old foe. All true; no lies. All true. And no black was permitted to travel into any of the states of the Hard Four without a white companion to vouch for his whereabouts and be responsible for his conduct. I needed a white person. "

― Ben H. Winters , Underground Airlines