The story centers on White Satin, a pony whose name reflects his "white and smooth" coat. His life on the farm is defined by his bond with Patty, whom he takes for rides either on his back or in a "little red pony cart." However, the arrival of a "big blue car" disrupts his sense of security. White Satin harbors a deep-seated fear that the machine will "run into him and hurt him." His resentment grows when Patty and her father leave him behind to go to town in the vehicle. Feeling abandoned, he concludes, "They do not want me anymore," and decides to "run away."
Driven by impulsive frustration, the pony escapes the barn. His journey leads him to a pond, where his attempt to get a drink turns into a life-threatening ordeal. Upon jumping in, his "four feet were stuck in the soft mud." This entrapment is punctuated by the mockery of the frogs, whose voices range from the "gruff voices" of the grandfathers to the "little high voices" of the wee frogs. Their taunts—"Never get out" and "Going deeper, going deeper"—mirrored the pony's own growing despair as he realized he was "stuck fast in the mud." This segment serves as a metaphor for the dangers of acting out of anger; the pony’s escape attempt leads him into a trap far worse than his perceived neglect at the barn.
The turning point occurs when the farmer’s dog alerts his master to the commotion. Upon discovery, the farmer recognizes the animal as "Paddy Green's pony" and initiates a rescue mission. The irony of the situation is profound: the very object of White Satin's jealousy, the "big blue car," becomes the instrument of his salvation. Patty's father arrives in the car, and the men work in tandem, using "strong ropes and boards" to create a platform. By tying the rope to the car, they utilize the vehicle's mechanical power to pull White Satin from the mire. As the car pulls, the pony’s feet emerge with a "Splash!" and he is finally "safe on the ground."
The aftermath of the rescue marks a significant character arc for White Satin. After being brought home, Mr. Green meticulously cleans the "black mud from White Satin's coat" and warms him. The following morning, the reconciliation is complete. When Patty visits him with an apple, White Satin’s behavior toward the blue car is transformed. Instead of the hostility he previously displayed—where he would "shake his head and snap his big white teeth"—he demonstrates gratitude. By rubbing his nose against the "bright new car," he acknowledges the vehicle not as a threat, but as the partner that helped secure his safety. The story concludes with a heartwarming resolution, showing that through adversity, White Satin learned to overcome his prejudice and appreciate the harmony of his life on the farm.