When that shrewd conniver, Tom, the infamous Great Brain, is sent to school in Salt Lake City, his favorite victim, J.D., figures he can step into his brother's shoes as town hustler. Nothing's wrong with his technique—it's just that he hasn't got the instincts of a real con man. But when outlaws kidnap J.D.'s four-year-old adopted brother, Frankie, J.D.'s talents find their proper inspiration. And if everybody thinks it looks like curtains for Frankie it's because they haven't counted on what a "little brain" combined with a big heart can do.