In the early hours of the morning in a quiet Milton Keynes street, a single bullet was shot through an open window. The victim was a 19-year-old man. What followed was a frantic 999 call and an investigation by Thames Valley Police to find the culprit. This documentary follows the case as the detectives try to piece together the moments leading up to that fatal shot. But it soon turns out there is more to the inquiry than meets the eye with a potential second suspect.

Cameras follow Thames Valley Police's investigation into the murder of 64-year-old Hang Yin Leung, who died after being violently assaulted during a burglary at her Milton Keynes home in January 2017. Filmed over 12 months, the programme interweaves the police's enquiries with an intimate portrait of a British-Chinese family coming to terms with the impact of murder, with the story of migrants from Hong Kong who came to the UK in search of a better life for their son unfolding alongside the hunt for the killers.

When Peter Farquhar passed away, no one was suspicious. But later, after the death of his neighbour, the police discover an almost unbelievable story of love and betrayal.