"There are moments that make murderers of us all. No one is safe from the worst they can do."

As events spiral out of control, Jefferson Grieff prepares to face execution, and time is also running out for Janice Fife in the cellar. An increasingly desperate Harry Watling struggles to do the right thing, but can he stay on the side of the angels and still keep his wife and son safe?

"People say they're Christians, but you know what? You never see them nailed to anything."

As Harry's dilemma worsens, the fate of his family hangs in the balance - but he's determined to do the right thing. Meanwhile, Beth Davenport meets one of Jefferson Grieff's helpers in the outside world, who delivers a chilling warning. In the cellar, Janice's desperation grows. In her battle for survival, is there anything she isn't prepared to do?

"How do you physically, on purpose, actually make someone die. Have you ever thought about that?"

How far is maths tutor Janice Fife willing to go to make her escape? On death row, journalist Beth Davenport finds herself running an errand for the wife killer Jefferson Grieff. And vicar Harry Watling confronts his verger about a dangerous secret.

"Everyone's a murderer. You just have to meet the right person."

In the US, a prisoner on death row is seeking atonement as he faces execution. On a train in England, a journalist is looking for a story. In a quiet little village, a vicar is picking up his son's maths tutor from the station. All four are about to become entangled in a dilemma that could lead one of them to murder.