Barney adds a true Blue detective to the Mayberry police force ("Barney's Bloodhound," Episode #128). Barney and Blue are quite a team as they successfully track down an escaped prisoner. (No doubt the "Wanted" poster Barney shows to Blue does the trick.)
To no one's surprise, it's the convict who ends up capturing Barney. But have no fear, Blue comes to the rescue - just as slick as a whistle.