Case 1: During 2014 and 2015 an organised gang of fraudsters were targeting the elderly by pretending to be the police. Asking their victims to withdraw large sums of cash that would be collected by a ‘police courier', the gang set out on a nationwide crime spree in which police forces from around the country joined together to bring the criminals to justice.

Case 2: When Alison Saunders bought a struggling company that helps children and young adults get prepared for the workplace she made sure her nearest and dearest were by her side. However, what Alison didn't account for was the fact that one colleague, Terri Hardman, didn't have her best interests at heart and was working to unravel her efforts.

Case 1: Leicester, 1986. The body of 15-year-old Dawn Ashworth is found following her disappearance. The murder is almost identical to the killing of Lynda Mann in 1983. Detectives in charge call on the help of Professor Sir Alec Jeffreys who had just discovered the DNA fingerprint. The police obtain the killer's DNA and the hunt is on to catch him before he can kill again.

Case 2: In March 2016 Jess convinces her best friend Laura to join her and members of her running club on a Monday night jog. Little did the girls know that also on the road that same night was a courier transporting a deadly package. The man loses control of his vehicle and hits the girls, leaving them fighting for their lives.