In July 1950, Ma and Pa Kettle come home after their fun and exciting trip to New York City only to find out that they're going to become grandparents.

Ma and Elizabeth don't get acquainted very well—which is the reason why the Kettles leave their ultra-modern house to return to their beloved ramshackle farmhouse.

While Pa and his Indian friends, Geoduck and the mute Crowbar, go to work blasting a new well, two shady men searching for uranium deposits find evidence of the ore in the farm soil.

Mr. Parker, a retired mine owner who, unlike his wife, appreciates the Kettles' hominess, deduces that Pa's radioactivity must be due to uranium-rich soil in his coveralls pockets.

She and Ma, however, do not disembark in time, and are forced to stop the train in the middle of a field and use a railroad hand car to get home.