River

Scotland Yard's Inspector River and his partner Stevie were in pursuit of a man. He was a key witness in Stevie's murder. River, who can communicate with the dead, investigates with Stevie, who is now dead. However, the man he is chasing falls to his death. River teams up with his new partner, Ira, and begins investigating a new case.

Lieutenant River obtains security camera footage from the scene of Stevie's murder. However, he discovers something strange in the footage. When Stevie's DNA is found in the car of Riley, a drug dealer who fell to his death and was a key witness in the case, River begins to suspect his trusted partner.

Lieutenant River begins to analyze the cell phone hidden by the murdered Sgt. Stevie. He finds that he had contacted his brother Jimmy, who was supposed to be estranged from him on the day of the incident. Jimmy, an Irish immigrant and former gang member, had just been released from prison after being imprisoned for murder by Stevie.

One of the last of the cell phone records hidden by slain Sgt. Stevie is revealed. It was Tom, the husband of River and Stevie's boss, Chief Inspector Chrissie, and a judge. River questions Tom, but the truth remains unclear. A person of interest, Haider, is murdered, and River's partner, Ira, is attacked and seriously injured by someone.

[Season Finale] Sgt. Stevie was investigating several companies before he was murdered. As the mystery deepens as to why Stevie was working in secret, a connection to an unexpected person is revealed. There, an injustice that shakes the Metropolitan Police Department comes to light, and a shocking truth is revealed that was stored on the computer he left behind.