DC Rob Brady and Trainee DC Billie Fitzgerald respond to a gruesome scene: a man found stabbed multiple times and left hanging from a tree. DS Vivienne Cole expects to lead the investigation but is shocked when DI David Bradford takes over, as he has been on leave since the disappearance of his wife.

DC Rob Brady and Trainee DC Billie Fitzgerald respond to a gruesome scene; a man found stabbed multiple times and left hanging from a tree. DS Vivenne Cole expects to lead the investigation but is shocked when DI David Bradford takes over, as he has been on leave since the disappearance of his wife.

A man is found murdered on his houseboat, but the woman who alerted police has fled the scene. When Vivienne and Billie question the victim's widow, they discover he was having an affair with his best friend's wife.

When the body of a woman turns up by the river, the detectives track a suspect through a dating site, only to find he may have shot himself. While Rob and Viveinne disagree about whether it was a murder-suicide, Billie worries about Amber, a witness in another case.

With Billie stabbed and her attacker on the loose, Vivienne blames herself for not recognizing that Billie was in danger. As the team scrambles to track down Amber, they discover that there's more to her than meets the eye.