Land of the Giants

Fitzhugh, looking for giant seafood, runs afoul of a giant deaf boy whose father is a poor fisherman. He escapes, and Valerie and Betty return. They and Steve are forced to take refuge in a giant seashell, which the boy takes home. They are discovered. Worse, the boy has excellent eyesight and manages to track Fitzhugh back to the Spindrift!

The family gets the spaceship although the rest of the Earthlings escape. The father is eager to turn the little people in for a reward to put his son in a special school. When he leaves, Steve bargains with the mother: they'll make a hearing aid for the boy in return for their freedom. Initial efforts prove unsuccessful, leading the father to believe they're lying.

Mark eventually figures out they need a shell for an amplifier. The father is in too deep with the local authorities, so his son takes the ship without his permission and hides it in a different location. The mother convinces her husband not to pursue the matter, hoping the authorities will understand since they tried to stop their son and failed.