Martin Barrett is not a very popular man so it's no surprise to the locals when he is found shot dead in his kitchen. Whilst investigating the homicide, Barnaby and Jones uncover the fact that the late Mr. Barrett was very adept at blackmail and that several locals were targetted for his attention.
The problem for the police is that Barrett had set up so many people to blackmail that they aren't sure who, if any, are actually responsible for his death. Could it have been the rich businessman who had his hand in the smuggling trade or perhaps an esteemed member of the Police Board? Then again, maybe it was somebody else entirely who wanted the unscrupulous Barrett dead.
You'll have fun finding out so watch and enjoy.