My current sim is a doctor who extremely smart but very anti-social. Lives in an upscale cliffhanger high-rise in uptown. He works when he wants and the rest of the times he's either playing basketball or listing to music and drinking while looking at the nightlife of the city.
One day at work he gets a patient with several symptoms he can't figure out. A few days later the ER is filled with sims of mysterious bite marks, lost time, and lack of control over their own body. All the sims told my doctor that they had each visited (or been visited by a person from...) a place called forgotten hollow. The national sim regional registry had no mention of a forgotten hollow.
So my sim decided to investigate, he asked the patients for directions to the old town. When he got there he started questioning the local residents about the symptoms he witnessed in his hospital. The residents smiled and told him they knew nothing about it. The last resident at the top of the hill seemed intrigued by the young doctor and invited him in to chat. But really it wasn't a chat at all, it was an interview for a new "position" in town. My sim was unaware that this was an interview and the the resident in question was Vladislaus Straud the founder of forgotten hollow.
After speaking with the young doctor (my sim), vlad thought he would make an excellent apprentice (and an excellent addition to his collection in town). So he made a deal, he would give my sim the answers to how to cure his patients, in return my doctor would have to do a weird favor for vlad. He would have to take some plasma from vlad's veins and drink it. Very strange but it was the only way to get the answers he wanted.
So he did it, and likewise vlad pulled out an old leather tome covered in dust. He turned the pages and ripped one out, and handed it over with a smile. My sim returned to his penthouse with a herbal remedy to cure this strange disease. A few days later it seems that favor was not a favor at all. It was a ruse.
Vlad had no intention of ever letting my sim leave without the knowledge that he would be back, and that he would be much different than when he arrived the first time.
Anyways I think its a neat story and a perfect line up to start my run.