The pleasure of grifter movies is vicarious criminality; a chance to become conjoined to that lifestyle that seduces with everything from slight of hand (fluffing childhood magic fantasies) to the elaborate long con, which in movie terms means an unreliable narrative. The film itself becomes a confidence trick. From Ocean’s Eleven to the BBC series Hustle, we’ve seen teams of well-heeled thieves execute rug pulls, leaving rich victims open mouthed. All those elements are present and correct in Will Smith’s smug new movie but so too a nagging feeling that both he and his cohorts are a thumb’s width from being odious. Perhaps that’s because many of their early marks are ordinary Joe and Jolenes with a weakness for gambling (Smith’s character hypocritically has the same problem), and we can almost feel their hands in our pockets, or perhaps it’s the almost self-congratulatory exchanges between Smith and lover/protégé Margot Robbie, but regardless it hurts the movie. You don’t want to be any of these bastards.

Focus enjoys not one but two directors. One wonders how Glen Ficarra and John Requa shared the gig. Was it Ficarra’s job to draw the eye with the movie’s elegant, glossy compositions, while Requa orchestrated the theatre under the audience’s nose, or did they take half a movie each? If the latter, that may explain why Focus breaks so suddenly at its mid-point, like the proverbial doomed ocean liner, the, er, focus of the story shifting wildly to a new location, time and con, just as we’ve started to invest in the self-involved Smith and his burgeoning relationship with Robbie’s arm candy.

The restart means a loss of momentum from which the movie never fully recovers. The hope must have been that Smith’s sudden (and never fully explained) decision to cut Robbie loose would add a little tension and rivalry to the great deception that closes out the second hour, but it’s hard to concentrate on the particulars of the contorting plot when you’re frustrated by character motives that seem plot driven, rather than psychologically plausible. We simply don’t care enough about Smith’s character to indulge his ambivalence, as the star hasn’t done enough to sell the idea that he’s a tortured soul with a chequered past. Smith thinks it’s enough to smarm his way through, like the matinee idols of old, but it isn’t, and consequently his treatment of Robbie seems inexplicable rather than merely unfortunate.

The movie cons on, reaching its double bluff climax later than we’d like, but by then we’ve lost interest both in it and the sting that’s consumed the second turgid half. If Focus had been better focused, offering characters you could love rather than happily seen thrown into a Mexican prison, then it might have been a winner. But it wasn’t, it didn’t and it isn’t.