Pcs Sally Armstrong and Tony Stamp arrive at the scene of a road accident involving two men, Cliff Taylor and Dennis Jackson. As Cliff’s Ukrainian girlfriend Rita is taken to hospital, Dennis is arrested after refusing to give a breath test. Then a Magley Motors repair van turns up with an undercover DC Terry Perkins on board. Terry's onto Helen Magley, a loan shark who orders acid attacks on those who can't pay. When DI Neil Manson learns that cash-strapped Dennis bought his car from Helen, he visits Dennis. And when Dennis's daughter has acid thrown at her, Dennis admits that Helen got him to cause the morning's accident for an insurance scam. Still undercover, Terry finds out the name of the vicious thug used by Helen – Steve. Helen and son Si are hauled in for questioning where Si cooperates by calling Steve to arrange a meeting. When Neil and the other officers turn up, a furious Steve grabs Pc Beth Green and threatens to spray acid in her face. At the hospital, Tony and Sally quiz Cliff and Rita but when Rita is unable to provide ID, she flees. Later, the officers attend a disturbance at a Ukranian cafe where Cliff is arguing with the owner. Sally spots Rita hiding across the road and as she tries to capture her, Sally finds bruises all over Rita's body.
