Here’s one for anytime after the Great Depression onwards to space faring days.
Smilin’ Joe, the local used transportation dealer (car, hovercraft, space ship, etc.) sells the PC a car. However, the PC is no further than three blocks/parsecs from the dealership when they are pulled over, promptly searched and found to be transporting a tidy sum of illegal drugs in the spare tire (or engine room if a space ship.) Smilin’ Joe claims innocence and now the PC is in hot water with the law. Some unnamed benefactor bails the PC with a note telling them to be at a certain location within a few hours. What can all this mean? Is PC going to get back at Smilin’ Joe somehow? Who is the mysterious helper? The PC (and his comrades in arms) will have to find out as the adventure unfolds.