Woody Allen’s (Midnight in Paris) latest film is never more than the flimsiest of trifles, but what a diverting trifle it is. Colin Firth’s (Before I Go to Sleep) Stanley is a stage magician and debunker of spiritualists who is called to the French Riviera by an old friend (Simon McBurney: Tinker Tailor Soldier Spy) in the hopes that he can poke holes in the act of vibration-receiving, spirit-contacting Sophie (Emma Stone: The Amazing Spider-Man 2), who, astonishingly, appears to be the real deal. It is the 1920s, the last hurrah of spiritualism and seances, when, perhaps, a “militantly scientific” mindset like Stanley’s was beginning not to seem like a total buzzkill. And yet Firth makes an absolutely hilarious curmudgeon, full of — yup — Darcy-esque reluctance to admit that he finds young Sophie rather more fetching than he should, given his stance on the nonexistence of spirits and ectoplasm. The discussions about the virtues of not giving in to pleasant fantasies about life after death, no matter how appealing they may be, are old hat, and the thrust of Stanley’s story — about how a man can find a new lease on life via an attraction to a 30-years-younger woman — is a bit icky, given what we know about Allen’s own predilections. But I am a total sucker for this era — the clothes! the cars! the music! — and the completely gorgeous re-creation of the period was more than enough to carry me down this blithe, ridiculous road.