CID investigate a spate of car thefts, and DS McAllister's informant Jamie Ross gives her a tip-off about a gang of French car thieves working in the area. Ross is reluctant to name his contact though, who turns out to be Joe Riley, DC Paul Riley's brother. The gang is arrested, but are broken out of Canley Crown Court by a trio armed with shotguns. An SO19 raid on Joe Riley's lock-up sees them in custody again, but DC Riley must work hard to hide his brother's involvement, particularly as Ross informs McAllister that it goes deeper than Riley thinks.