Pcs Nate Roberts and Mel Ryder attend an incident on a bus where a man has been stabbed, and find terrified passenger, Holly Perkins, trying to stem the flow of blood coming from Kelvin Gainham’s wound. Nate rushes to Kelvin’s aid and, as Kelvin is taken to St Hugh’s Hospital in an ambulance, Nate quizzes Holly about what she saw.

Holly reveals that Kelvin and another man fronted each other and, as she tried to calm the situation, a knife was pulled and Kelvin was stabbed. Impressed by how keen Holly is to help, Nate is later surprised to learn that she is DC Terry Perkins’ daughter. But Terry is none too pleased when Nate and Holly seem to bond as she helps in the search for Kelvin’s attacker.

When Kelvin dies, the case becomes a murder investigation and the hunt is on to find prime suspect, Jed Ryan. During the search, Terry is horrified when Holly disobeys Nate’s orders and finds herself confronted by an emotional Jed…