Focus is a double-cross comedy that doesn't quite work. Will Smith plays Nicky, a third-generation conman and leader of a sizable crew of fellow swindlers who prey on unsuspecting marks at big sports venues. Margot Robbie is Jess, a minor-league con girl with an eye on the big time, and on Nicky as her chosen mentor. The stars have a road-tested appeal—Smith with his familiar jaunty charm, Robbie with the sunburst beauty and tangy comic instincts she so memorably displayed in The Wolf of Wall Street. The locations—New York, New Orleans, Buenos Aires—are passably glamorous, and some of the rip-off techniques are fun to watch. The setup primes us for a movie that sparkles with breezy romance, light-hearted larceny and deluxe travel accommodations. Unfortunately, that movie never fully arrives.