The Secret of Castronegro is a short scenario for Call of Cthulhu published in the supplements Cthulhu Companion and Cthulhu Classics. Here are the thoughts I had after running it. The following notes have all the spoilers and no context provided.
I heard of this scenario from an episode of the Fear of a Black Dragon podcast, and many of the following notes originated from it and one of the hosts Jason Cordova's actual play recordings, which can be found on Youtube (hence called "J"). I really liked it, but there are a couple of changes I made, and I had a LOT of thoughts after playing it. I ran it in Cthulhu Dark in two sessions, the first 3 hours and the second only 2 hours.
Like J, I moved the Silver City section to a pre-session thing. I gave each player (I had three) a mystery they were investigating, which were the three missing persons: Dr Godfrey, David Lane, Joaquin Vilheila-Pereira. On reflection the fact that everyone had a missing person was a bit begging suspension of diebelief but it wasn't too bad. The other options were the cattle mutilations and the missing babies, of course.
I did this using play-by-post over Discord, starting with Dread-style questionnaires, then everyone making a few investigation roles as per CD. Here's one:
The setting is 1920's America. It's still the Prohibition, small towns don't have phone lines or much electricity yet.
1. You knew someone in Albuquerque, New Mexico, an abbatoir hand by the name of David Lane. He always had a faraway look about him, like he was looking for something, mulling something over. He’s been missing for a few days now. Kidnapped, they say. Who was he to you? Why are you looking for him? What do you remember most about him?
2. What do you see that haunts you in your nightmares?
3. Do you believe in monsters?
4. What is your occupation?
5. What is your name?
I made a few changes to the characters. More on that in a minute.
I realised that separating the threads like this makes it a bit harder for each PC to collect enough clues and therefore have enough plausible motivation to go to Castronegro, but that was fine since I had established that that was where we would end up.
This process made me learn how much I DETEST play by post. It was only maybe a dozen messages back and forth for each player but as someone who tends to hyperfixate on games this made me think about the game CONSTANTLY for about two days straight. Discrete time blocks please. If I do something like this again I'll schedule voice calls or something.