FairySlayer

What is the story about?

It's a dark "Phineas and Ferb" (Disney cartoon) fanfic starting when Candace (the teenage sister) gets home from two weeks in the hospital after a major meltdown. (More than usual.) Being heavily medicated makes her easy pray for her stepfather, but there's a lot more going on too.

I'm having trouble getting one of the pairings into action: the fuel and air are together, but I'm getting weak spark.

It probably won't make much sense if you have...

I'm familiar with the cartoon at least. Tell me about some of the other things going on...