Because of the time travel in one of the movies, there should be some kind of order to these for it to make sense. So the plot from Frankenstein’s Army would be the first part. This would probably be followed by The 25th Reich, and finally Nazis at the Center of the Earth.
Part 1 – Inspired by Frankenstein’s Army
BASICS: During a war (World War I), a special team is assembled to hunt down Dr. Falkenstein, a mad scientist from the other side of the war. Their orders are to capture or kill, with the emphasis on capture. All they know is that he is delving into sciences that go way beyond modern science and their side wants a piece of that. For reasons I will explain later, I think this will best work in a World War I like setting.
Traitor: At this point, the GM can come up with a Traitor if he wants. Determine their motivations and the back story. It does not have to be totally contrary to the rest of the party. It could be just a secondary goal that has to be accomplished or something along those lines.
PUSH/PULL
This is a military mission, so the initial PUSH is the assignment of the mission. All good soldiers should do as they are ordered, right?
These collectively would be (1) the initial investigation encounters to find the Doctor and (2) the Encounters when getting to the facility. The pathway to get to the Doctor and his facility is a hunt and in that hunt, clues will be found. Simple clues can be found with simple gathering of information or networking with contacts but the important clues should involve an encounter. The initial PUSH is the assignment of the mission but also the investigation. In the movie, the journey to the Church is part of the PUSH – the village and the area outside the Church.
In the RPG adventure, this can be anything but I would lean towards similar tropes the movie used. The Doctor is using the War and the village for his strange experiments. The people around his facility area all scared and call him a monster. It is very tropey but still works for an RPG adventure.
“The Investigation” does not have to take place in a Village but I am using that as a metaphor for whatever it ends up being. It could be a military outpost of allied troops. It could be a convent of monks. In the PUSH, the party learns of the Doctor and his strange experiments.
Idea: Implanted within the villagers is a Minion of the Doctor, who can act as a friendly face in the village but is actually a traitor. This Minion – an Igor type – is probably modified in a very subtle way and is probably a former villager who disappeared and came back (villagers are suspicious of him/her).
The PULL is when they arrive inside the Facility (Church or Castle or whatever). This is the crux of the adventure and the GM needs to have this detailed out to some degree. In my idea, set in WWI, it would be a Castle somewhere in the Austrian mountains, close to the mythical crash site of the alien craft. Falkenstein moved the craft from the crash sight to the castle in the early months of the War and has been there ever since.
The important thing is the details of the Facility and what the Party is going to face. In my idea, I am going to start them from the bottom up. From the investigation (in the Village, perhaps through the Minion as a set up), they will lead
GIMMICK
Drawing from my original adventures that were similar to these, I would say that the Doctor is working with alien technology. In my adventure series, it was alien nanite technology. Because this is going to involve the alien technology acquired by Nazis, this is a good start. Dr Falkenstein has integrated dead bodies of the front (shipped to him by allies within the German war department) with nanite technology to re-animate them into super soldiers, integrating them with technology of the era. Unfortunately, he has not perfected it and has created many mistakes. He uses the catacombs beneath the Church to store his mistakes. These Mistakes are encountered by the party as they infiltrate the castle from the bottom up.
Mistakes
Inspired by the creatures in the movie, the GM is free to create a menagerie of types, each harder than the last. I love the idea of integrating with modern tech and in an RPG, you are lot limited by budget or special effects capabilities.
Time Travel
To Escape the players as they finally get to him, he jumps through time, through a gate. He set the Facility to explode so the players have only one choice – following him through to his next time period. Unfortunately because the science is not precise, they appear in a slightly different time after Dr Falkenstein.
ENIGMA
Dr. Falkenstein is from the future. He found the time machine in the wreckage of a hidden Nazi bunker and realized that the Nazis did not know what they were doing. Once he figured out what he had, he decided to go back in time to capture the technology before the Nazis and develop it for himself. Being a Nazi sympathizer himself, he planned to have it fully developed by the time World War II rolled around.