For more than 65 years the grimy Victorian painting, depicting the abduction of Persephone by Pluto, hung in the library of the Center School in Old Lyme, Conn., pretty much ignored by all—except the occasional spitball-spewing schoolboy. But in 2000 it caught the eye of then-10-year-old Bingham Bryant. "I like Greek mythology," he says. "I wanted to find out more about it."

Bingham enlisted the help of his father, Christopher, 40, a dealer in military antiques. As a result of their sleuthing, the painting, The Fate of Persephone, an 1878 oil by British artist Walter Crane, sold June 12 at Christie's in London for $560,000. "I had no idea," says Bingham, who will get an undisclosed finder's fee, "it would ever turn out like this."

It took the Bryants two years to trace the provenance of Persephone, loaned to the school in 1935 by Yale professor Brian Hooker, and locate its legal owners, Hooker's two surviving daughters, one of whom, 84-year-old Pamela Thomas of East Haddam, Conn., attended the auction. Acting for the heirs, Bryant Père had the painting restored and shipped it to Christie's, which installed a new frame around the 4-ft.-by-9-ft. canvas. "We were aware that my father loaned the painting," Thomas told The Philadelphia Inquirer. "What we didn't know is how much it was worth."

Says Bryant, a widower who is moving his family to England in August to be near fiancée Lucinda McAlpine: "The painting has been brought back to life, the sisters get their inheritance—and Bingham and I had a lot of fun." Bingham is off to a British boarding school, where other hidden treasures may languish. "I'll be keeping an eye out," he says.