Advertising executive Gwen Taylor sends her art director Rick Todd on a mission to bring an artist back to the commercial fold. Meanwhile, Gwen's fatherless son Timmie, at a remote boys' school, is riding for a fall by manufacturing evidence of his "explorer father." By an amazing coincidence, Rick steps off the bus at just the right moment for Timmie to recruit him as "father" without his knowledge. With no intention of collaborating, the befuddled Rick is carried along by the sweep of events. Who can predict the outcome?

In New York City, advertising executive vice president Gwendolyn Taylor, a widow, chastises her award-winning art director, Rick Todd, for his sudden lack of interest in his job and orders him to travel upstate to Winawatamie to convince commercial-artist-turned-sculptor Mike Wyman to return for one more campaign. Although Rick, a former painter, secretly envies Mike's decision to forgo money in favor of personal satisfaction, he agrees to the trip. Gwen then receives a letter from her young son, Timmy Harkinson, who lives at The Meadows boarding school in Winawatamie. Gwen works day and night in order to make enough money to quit advertising and live with Timmy and, in addition to the many exotic gifts she has sent him, Timmy now requests an elephant tusk. At school, Timmy uses his artifacts to concoct a complex tale of an adventurer father, but the school bully, Freddy Doobin, accuses of him of lying. When Timmy's roommate, "Owly" Kimmel, informs his friend that Freddy has obtained a sample of his handwriting and plans to compare it to the next letter from Timmy's dad, hoping to prove that Timmy is writing the letters himself, Timmy rents a typewriter to thwart him. Freddy still suspects him, however, and after the bully reveals that the photo of Mr. Harkinson is really a magazine ad, Timmy punches him and vows that his father is coming to visit that day. Headmasters John and James Fusenot hear the news and joyously prepare for the arrival of the great man. Followed by the schoolboys, Timmy waits in town for the bus to arrive, and when Rick steps out and bumps into him, Timmy tags along with him to his hotel. Once there, however, Rick kicks him out, and Timmy tells everyone that his father is ill. Convinced that Timmy's parents are estranged and neglectful, the charitable Fusenots visit the hotel the next day, informing Rick's assistant, Larry Tripps, that his son misses him. When Larry later accuses Rick of abandoning his child, Rick assumes he is being set up for a paternity suit and hurries to the school. Timmy intercepts him and explains his fantasy life, begging Rick not to expose his lie. Countering that Timmy must face the truth, Rick strides into the school, but upon seeing all the boys waiting for him, cannot bring himself to disappoint the boy. During a luncheon in his honor, Rick rises to the occasion, impressing the students with detailed stories of jungle adventures. Later, Timmy rescues Rick from the Fusenots' lecture on parental responsibility, and Rick asks the boy about his mother, whom Timmy calls Gwendolyn Harkinson. The next day, James talks Rick into leading the boys on an overnight hike, and although he is hopeless in the woods, Timmy gives him hints on how to impress the kids. At night, Rick and Timmy sit together near the fire, and after Rick draws a picture of Timmy, the seven-year-old wonders aloud why Rick, as a grown-up, does not choose to work at what he loves. A newly inspired Rick fails to entice Mike into working for the advertising agency, and returns to New York to search for Timmy's mother. He cannot locate her, however, and when Gwen reprimands him for his contempt for advertising, he announces his resignation. Gwen, knowing this will set back her retirement date, breaks down in tears. Rick soon moves to Winawatamie, where he paints and sees Timmy every weekend. The two form a close, loving bond, and Mike urges Rick to paint from the heart, using the boy as his subject. One day, Gwen visits the school unannounced, and upon learning that her son is with his "father," calls the police to report a kidnapping. They escort her to Rick's, where the two adults recognize each other and call off the police, only to fall into a heated argument. Gwen insists on leaving with Timmy immediately, but the youngster deliberately disorients her, and she is forced to return with him to Rick's. There, she falls into the lake and then spills stew on her lap, and although she is at first furious, she finally laughs along with Rick and Timmy. Rick notes that, without her severe clothes or hairstyle, she is a beautiful woman, and later she admires his paintings, especially the heartfelt portrait of Timmy. She reveals her plan to work only long enough to support Timmy, but Rick suspects that she is tricking him into returning to the agency, and she goes to bed. When Timmy then comes out for water, he informs Rick that he has known of his mother's plan for months, after which a guilty Rick stands outside Gwen's bedroom door and offers to help her find a replacement art director. She turns down his proposal, and Rick sputters that he will return for a few weeks, and only for Timmy's sake, prompting Gwen to calmly open her door and kiss him. A few days later, Rick and Gwen return to New York together, promising that when they return, they will all live as a family. As Timmy blissfully waves them off, the schoolboys sing out bird calls to express their pleasure.