The Bill - Season 13 Episode 9 Once Bitten

When an ex-girlfriend of Sgt.Boyden who left him several years earlier because of his refusal to quit the police is arrested and brought in Sun Hill Matt finds himself caught between his feelings for and DS Grieg's investigation into a drug smuggling ring run by her husband and her brother in law, but it soon becomes clear to him what he must do when not only does Grieg's investigation implicate her it also looks like she has lied to him about why she left her husband but also that she may be using him to find out how much the police know about her involvement and to help her avoid getting arrested.