This episode works extremely well because it remains so focused on its plot, characters, and the basics of the Munsters' interaction with the outside world.
The city needs to put a new gas pipeline beneath suburban homes, including the home of the Munsters. They figure that 25 feet below ground should be more than sufficient, but little do they expect that they Munsters have a dungeon far below ground, which they accidentally break into. At the same time, the city official in charge of the pipeline, Borden T. Pike (Richard Deacon), has employees who are telling wild stories about the Munster house and a wife who keeps accusing him of fooling around.
The events have the Munsters effectively playing a shell game with Pike. When Pike finally sees the Munsters for himself, he figures they're just trying to scare the city into coughing up more compensation money. There's a funny moment when an unexpected Munster shows up for an appointment, and there is a lot of well-done ancillary material establishing the Munsters topsy-turvy view of the world, such as thinking it's beautiful weather when it's stormy. Pike's Pique also has a lot of interesting things to say about trust, including the extended climax with shifting expectations and attempts to cover up various levels of mistrust.