Satan's Sister

'Twin girls, one with the hair of chocolate, the other the hair of gold; both boys and girls shall have her names. One shall save the world, the other the destroyer; find the girl of chocolate hair before the man with red eyes does, for she shall have the key to the story that has never been told.'

Tyler Raines is on the run, but she doesn't know why. Her sister, Tayler has been missing for a few weeks and they think she's linked to the disappearance. Tyler and Tayler didn't necessarily see eye to eye, even though they're twins.

Ryan and Devon Marx are Dr. Rasper's assistants who are put on the case to help dig inside Tyler's brain. They go along with it for a while until they really meet her. Ryan can't stand her, but Devon is intrigued by her. They, then, realize that she's not who everyone thinks she is. She's the nice twin and people have been seeing her wrong.

When someone threatens her safety, they hide her and try to keep her a secret until they can figure out who wants to hurt her and find Tayler. After awhile, it seems that they both have feelings for her, but don't know what to do. Tyler doesn't know who she has feelings for and feels bad that she can't figure out who to be with.

Feelings aside, she has to fight for her own safety and fulfill the prophecy before Tayler finds her and kills her, winning the title as Satan for the rest of her life.