A recently qualified response driver in Westminster gets his first chase at 4am when a 17-year-old who has stolen his mum's car refuses to stop.On the hottest night of the year, a huge impromptu summer party in Hyde Park results in chaos. Police come under attack and there is also a vicious stabbing. Homicide and Serious Crime Command hunt the suspect.In Stratford, east London, a sergeant responds to the concerns of local residents by attempting to tackle the borough's prostitution problem.