I went to one of my close friends to help me think this through.
When we began we were throwing out broad story ideas. As we talked I narrowed down a few things. I started thinking I wanted a town adventure (a la Appaloosa or Open Range -- remember, just 2 PCs). But the idea of an adventure on a train kept interesting me, but so did some kind of hurry and deliver the Macguffin to the people. The more we talked, the more I realized I wanted something vaguely horror, vaguely supernatural, but not overtly either.
At this point barinstorming ideas wasn't really leading anywhere, so I used the funnel.
Adventure Funnel:The Goal: Deliver the Prisoner to the Destination [Intentionally left very vague at this point.]
Obstacles:- Indians
- Outlaws
- The Prisoner's Associates
- Wild Animals/ Monsters
- Blizzard / Weather
- Revenge Seekers
- Mechanical failure
- Delay [Not sure whjat this one was, but it's in my notes.]
So riffing on this and as we began to do details a firmer picture developed.
Details- The Prisoner is a cult leader
- the rest of his cult wants him back
- A Priest is sent to accompany the PCs
- They are taking the Prisonaer from the town where the trial took place to the prison
- they are going from a small town to a large town by train. Then by wagon/coach/horseback through the wilderness (terrain as dictated by narrative needs) to the prison.
- two "plot fodder" NPC deputies
So at this point we stopped and worked out the background of the scenario:
The Prisoner (later named Walter Odem) was a charismatic cult leader outside of Red Creek NM. Numerous bad events were blamed on Odem by the townspeople. From various illnesses, spoiling food, vermin infestations, freak accidents, etc. Finally he was arrested for arson, he suspected of killing three people, but it could never be proved conclusively. Red Creek citizens are so afraid of him at this point that they don't even want his ghost to haunt their town, so he is tried and convicted to serve 25 years in the Territorial Prison.
Our PCs, with a reputation for being experts in difficult prisoner transport, are sent to Red Creek, along with 2 deputies, to collect Odem.
A technique I've used for One-shots in the past is to have about 5 scenes prepped, knowing I could cut one if time is tight.
The PCs will take the train from Red Creek to Los Cruces. From Los Cruces to the territorial Penitentiary they will have to go by horseback. Along the way various weird things will happen.
Oh, and Walter Odem does have some kind of supernatural power. He draws power from having followers. If people believe he can do "miraculous" things, he gains the ability to do them.
I've been wanting to get back to Wild West gaming and this may be a nice set-up for a later short campaign when Walter escapes.