Marmaduke has yet again monopolized the time, energy, and finances of his family during one of their periodic day-long shore excursions, and it begins to dawn on them that they are essentially unwitting slaves, operating under the illusion that they have free will even though they are constantly doing the bidding of a gigantic dog.

Marmaduke has somehow obtained a very large television, which has led him to construct an addition to his doghouse.

Marmaduke is up to something, and his neighbors are justifiably concerned.

Marmaduke has passed out in his owner's lap, prompting a houseguest to comment that having an enormous dog capable of fully immobilizing you just by napping on you must be a "pain in the neck." Marmaduke's owner agrees with this, but qualifies that he is a "sweet pain in the neck," indicating that she has made peace with her decision to care for a hulking canine monstrosity who has no concept of her needs or well-being.

Marmaduke ruined a group of children's pickup baseball game by snatching away their ball and destroying it with his powerful jaws, and there is nothing they can do because he is humongous.

Marmaduke has somehow managed to re-obtain the blueprints for his proposed tunnel (see last Tuesday's Marmaduke for an example of the rich and multi-layered plotting at work here). The female neighbor is curious about the necessity of said blueprints, but her husband (who suffers from mild dementia) cannot recall what the papers refer to, or that he even confiscated them in the first place. Her question goes unanswered, save for his mute, distant gaze.

Marmaduke has established a pattern of sneakily cutting through his portly septuagenarian neighbor's home (rather than taking the time to walk all the way around it), but this time he has been caught in the act, and is informed that he's going to have to put an end to such practices.