If I can ever manage to write it, it could turn out to be just that. But today I'm thinking if I made the character have a wealthy father who dies....perhaps he's worth tens of millions....he has an interesting cast of family...a greedy self centered sister...a brother in law who perhaps is a mason....an estranged older brother who was written out of the will...

Perhaps this can be yet another layer of paranoia. Is it something unexplainable? Is it simply mental illness? Or is there foul play by others....a conspiracy.

Perhaps the character's father's death is supposedly by stroke...yet there was something suspicious about his death that only the character picks up on. And he finds his brother is now friendly with his mother...who is an extremely negative person who uses money to buy control, access, affection, and the right to judge her children.

That would bring possibilities for the plot that would make it more compelling to read about.