NPC got in the passenger of a car that had a broken driver side door. I got to the driver seat through the passenger seat, and the NPC climbed into the passenger seat. Several zombies came on over and killed the survior through the broken passenger window, and I was trapped in the car. I tried telling the NPC to 'return to base' as I DID have a base set, but the NPC simply stayed in the passenger seat of the car.