PC Worrell and PC Quinnan attend to a woman threatening to jump off a bridge. She turns out to be Sarah Collins, the wife of Terry Collins, a DS at Stafford Row CID. Despite the doubts of some of her colleagues, PC Worrell is determined to pursue the matter as a domestic violence case. She convinces Sarah to make a statement and testify in court by telling Sarah of her own experience with domestic violence. The case is dismissed, however - Sarah becomes reluctant to testify, and there are doubts about her character. When Worrell goes to check on her at the Collins house, she finds that Sarah has murdered her husband. Meanwhile, Dave Quinnan struggles to find the right time to tell his wife about his affair with Polly Page.