My Nightmare in Shining Armor

He's the local town terror. Supposedly he's killed people before. Supposedly... then again no one could prove the rumors were true. No one until her that is. They made a deal, her side with the devil.

As they started spending more time together she begins seeing things that alarm her. Random red splatters on the floor in his basement. A room no one has access to. A knife collection. All signs obviously point to the fact that he has a secret. The question is once she finds it out will she reveal it, or will it stay hidden as it was before?

She starts noticing he has more than one side. There is a head and a tails to every coin. Maybe this nightmare has two sides.

She doesn't know his deepest secret. She doesn't know what he did. But once she finds out who knows what she'll do to him.