There’s a decent occult/sci-fi novel series called the Laundry Files wherein people sometimes stumble across or come up with forbidden mathematics that actually functions as a form of occult spellcraft. They then get forcibly drafted into this secret government organization that works to protect the world from extraterrestrial threats, occult creatures like vampires and succubi, and the lovecraftian horrors from the depths of the oceans or the fridge fringe edges of space. They’re like the men in black crossed with Lovecraft crossed with a British comedy about monotonous office life and bureaucracy. It’s a pretty entertaining series. Highly recommend.