Craig Petrie becomes a suspect in both murders, and Blake assists in questioning him. However, he quickly turns the tables on the police and casts doubt on Leighton's innocence. Annie investigates his claims further, and her loyalty to Leighton is shaken when she discovers his alibi is a lie. Smilie tries to comfort Jonjo's father, but is rejected.
In a community nourished and sustained by myth and bordered by untamed nature, the search for a serial killer becomes a matter of life and death for local detective Annie Redford who is trying to cope with her first murder case. When the body of local man Niall Swift is found at the foot of Carn Mohr Mountain and an isolated human heart on the loch shore, the town's normality is shattered and the nightmare begins. Chillingly, the beautiful scenery, undulating Highlands and vast expansive loch becomes a character in it's own right adding a haunting depth to the community's plight.
The Loch - Series 1, Episode 4 Synopsis and Schedule