DCI Grace Barraclough first appeared with her colleague DCI Vikesh Dasari (Stephen Rahman-Hughes), as part of the storyline surrounding the death of Tom King (Ken Farrington). While investigating Tom's murder, she suspected Bob Hope (Tony Audenshaw), even more so after he confessed. However, it emerged that he had confessed to protect his son Jamie (Alex Carter). She later started dating Carl King (Tom Lister) secretly, as a honeytrap. Their relationship became serious, however if they were discovered, Grace could lose her job. She carried on with the relationship, but when Vikesh saw her with Carl he gave her an ultimatum; end the relationship or he would tell her boss Charles Vaughan (Richard Cole) and her career would be over. (Vaughan was already angry with Grace for failing to get a conviction on the King case, amongst other things). Knowing what she must do, Grace ended the affair, even though she still loved Carl.
After Grace ended the affair, Carl left the village, for a brief amount of time to get over Grace. When Carl returned however, he seduced Grace again. She tried again to end the relationship but when she learned that her mother had had a stroke, she regretted being so hard on Carl as he refused to be a shoulder to cry on. She stopped answering when he called; and later in the week, when Carl read about her mother's death in the paper, he resorted to waiting outside the police station and Grace's home in order to get her to speak to him. It finally worked, but she confessed that the first time they had had a drink together, she had followed him and was trying to trap him for information about the murder of Carl's father. Grace and Carl worked through their issues and their relationship was back on track. Grace died on 27 September after being hit by a lorry after Carl admitted to her that he had killed his father. Carl didn't attend her funeral but laid flowers at her grave later on. It was supposed that Matthew King (Matt Healy) had ordered her death.