Final episode in this gripping BBC drama tonight, written by Harry and Jack Williams, the duo behind gripping drama The Missing. It focuses on the aftermath of the murder of two childhood sweethearts who are killed on their return from honeymoon. Tonight, with Rob now in jail, Claire is still desperately hunting for answers and Adam and Grace's wedding video could hold the key to the mystery. However, she soon makes a shocking discovery, with the truth turning out to be more terrible than she could have ever imagined.