In 1950s England, slow-witted Derek Bentley falls in with a group of petty criminals led by Chris Craig, a teenager with a fondness for American gangster films. Chris and Derek's friendship leads to their involvement in the true case which would forever shake England's belief in capital punishment.

At the dawn of the 20th century, following their father's arrest on suspicion of betraying state secrets, the three Waterbury children—Bobbie, Phyllis and Peter—move with their mother to Yorkshire, where they find themselves involved in unexpected dramas along the railway by their new home.