Lord Ashfordly's game keeper Frank McCready is deep in debt with bookmakers and loan sharks breaks into Ashfordly Hall and steals the money for the staff wages. When his wife Mary finds out he promises her to pay every penny back, but she is afraid she will be regarded as an accomplice if she does not tell the police, what she knows. She sees only one solution to her problems with PC Bradley as an unlucky witness. Greengrass and David come across a stranded lorry loaded with bags of coal and the old scoundrel consider it their duty to salvage the coal according to maritime law - a very free interpretation on his part based on the fact that one of the wheels of the lorry is standing in small puddle of water. Not surprisingly nobody else sees it that way.