Don't leave me Alone

Katie had had a disturbing childhood. All linked to the disappearance of her dad. Until one day, she discovers she is going to have a step dad. She hates the idea and will do anything to stop what is going on. Failing to do so. She notices that after the wedding. Strange things keep happening to people who are close to her family. She instantly suspects her new step dad. But what if the person she should really be scared of is closer than she thinks.