Jackie struggles after her estranged sister returns and reignites years of guilt and betrayal, while Bull finds himself faced with two cases that are undeniably linked. A confession is made, but he suspects it has been designed to protect someone closer to home, while DNA evidence exposes a devastating truth and both Jackie and Bull must choose between protecting themselves or those they love.

In the midst of a violent storm, the residents of Morfa Halen form a search party. Jackie and Bull discover the horrifying truth behind the crimes that haunt the town. As Bull fights for his life and Jackie faces an unbearable choice, the storm reaches its peak and Morfa's darkest secrets are laid bare.