Mason is riding across the moors when he is flagged down by Nancy Beale who says her boyfriend, Billy Hudson, has fallen into the Scarsdale river. Mason wades into rescue him but it is too late.
Blaketon and Gina see Peggy slide a brown envelope under the door of the garage. Having received the same envelope, Gina shows it to Oscar. He decides Peggy has gone too far and the police should now be involved.
Meanwhile, the post mortem reveals Billy had injuries to his face, neck and hands, causing the police to suspect he may have been involved in a fight shortly before his death. Are the police now looking into a murder investigation?
When Mason and DS Dawson find out Billy and Nancy were blamed for the disappearance of Julia Summers, they begin to suspect it may not be a coincidence he fell off the same bridge where Julia was last seen. They discover from Nancy that Billy was meeting someone, but wouldn’t say who or why. Is this person behind Billy’s death?
Later, when Billy and Nancy’s son Peter goes missing, it seems someone is still convinced the couple are behind the disappearance of Julia. Will the police be able to find Peter before it’s too late?