Sheriff Mills is the law on Harper's Island. He's also Abby's father. He ended John Wakefield's deadly rampage seven years ago, but not before Wakefield took the life of his wife, Sarah. In his grief, Mills sent Abby away. Now that she's back for the wedding, he hopes to reconcile with her. But times have changed, and Sheriff Mills has some dark secrets that he has no intention of sharing with his daughter.