When her car breaks down on the way to the station, DC Viv Martella misses an important CID briefing about an obbo on a suspected armed robbery, and is furious when she is taken off the case by DI Frank Burnside. As CID and SO19 wait outside the target, Martella and PC Tony Stamp follow up a simple case to arrest a suspected bag snatcher. As they wait outside the suspect's house, a van pulls up, obscuring their view. Having missed the briefing, Martella fails to recognise the van's occupants as the armed robbers, and when she approaches their van she is shot and killed. Stamp is wounded, but manages to give a description of the van which is spotted by a traffic police motorcycle. As the India 99 police helicopter and SO19 cars pursue Martella's killers across London, PC Loxton and WPC Ackland disobey Ch. Insp. Cato's orders and pursue the suspect vehicle in the Area Car. The vehicle hits a bulldozer and explodes, killing all inside.