This plot as the title says the pairing I have in mind is a Terroist X Undercover agent pairing. I am open to other pairings as well. As far as The Four Horsemen I am watching a documentary titled that which talks about the fall of empires and relating it to the united states particularly what happens to talk a lot about the leaders of banks and how it effects the world. Also I think a good name for the terrorist group in this plot would be called the four horsemen for reasons I will explain to anyone interested in this idea.
Undercover cop / criminal X terrorist.
So the idea is that there is a group or single person who is targeting the CEOs of companies that they see as ruining the lives of the working class and running the country in the ground. So far the authorities have not even got close to catching them mainly because they have not been able to track the weapons that are being used to kill the targets. The first break the authorities get is when they find a gun that was dropped by one of the fleeing criminals. It turns out that the weapon was printed using a 3D printer including its ammo that are made out of a ceramic which solves the large question of how these criminals are able to get into buildings without setting off metal detectors.
For this idea I would see the criminals being based out of a college that has a 3D printer of high enough quality to produce the weapons if its based in present day. If we set it say fifty years in the future we could have it so 3D printers capable of making weapons are common house hold items.
I can see this idea going a few different ways but the way I think is most interesting would be that the undercover agent finding it harder and harder to not start believing in the ideals of the Four Horsemen.
This idea came about partly after watching a Vice documentary about 3D printed guns