While hot on the heels of serial coupon-racketeer Gordon Ginner, Chief Inspector MacDonald of Scotland Yard receives word of an intriguing incident up in Lancashire - the summer cottage of local farmer Giles Hoggett has been broken into, with an assortment of seemingly random items missing which include a complete reel of salmon line, a large sack, and two iron dogs from his fireplace. What first appears as a simple break-in quickly spirals into a mystery of contested land grabs for fishing between farmers, made all the more enticing to MacDonald when a body is then found in the river - the body of Gordon Ginner.