Weeks into hitting the beat, the trainees realise learning on the job can mean making mistakes in full view of a very critical public. Jack stops and searches an innocent couple after being told off for not being proactive enough, while Dan breaks a crucial rule when he runs into trouble on his first night shift, Julia's lack of experience in the drug world means she misses a vital clue when faced with heroin for the first time, and away from work she worries about her 22-year-old son, who has followed her career path and just joined up