“It was finally recovered last month, and investigators are focusing on several theories. And one of them is, in its own way, extraordinary: They are trying to determine if the heist was engineered by a retired New York City schoolteacher — something of a renaissance man — who donned women’s clothing and took his son along as his accomplice, and then hung the masterwork in the bedroom of his own rural New Mexico home, where it remained. In other words, they are examining whether he stole a painting now valued at in excess of $100 million simply so he could enjoy it.”