In Woody Allen’s “Magic in the Moonlight,” a famous stage magician (Colin Firth) sets out to expose a young psychic (Emma Stone) as a fake. This delightful period romp has the playful feel of a 1930s Cary Grant comedy; the story is set in 1928 amid the opulence of the Great Gatsby era on the French Riveria. 

Firth plays a successful stage magician known as Wei Ling Soo. Despite his Chinese stage persona, which allows him to be anonymous off-stage, the magician is actually a jaded, cynical Englishman named Stanley. Stanley delights in exposing psychics, who are wildly popular among the rich and gullible. 

Stanley agrees to help fellow magician Howard Burkan (Simon McBurney) expose a young psychic named Sophie (Stone) and her mother (Marcia Gay Harden), who have convinced a wealthy woman (Jacki Weaver) and her son (Hamish Linklater) that Sophie can contact the dead. Besides, it is a chance to visit his beloved Aunt Vanessa (Eileen Atkins) and have a little vacation on the luxurious Riveria.   

Stanley poses as a businessman and friend of Howard’s so as not to tip off the young medium or her mother. While Stanley remains skeptical of Sophie’s “powers,” he becomes baffled by his inability to detect her tricks. 

Director/writer Allen frames all of this in seductively lush, color-drenched visuals, from flower-filled gardens and a lovely seaside to graceful mansions, vintage cars and glittering, gauzy, ‘20s fashions. The film’s beauty seduces the audience as much as Sophie does Stanley. 

“Magic in the Moonlight” is full of twists and surprises, as much a mystery as a battle-of-wits comedy. But it incorporates historical details as well.  The idea of a non-Asian posing as a Chinese magician seems preposterous now but, in fact, there was a famous magician in the late 19th century who did just that. The turn of that century was the era of great stage magicians, including Harry Houdini. In the 1920s, spiritualism and seances were wildly popular, and Houdini became a debunker of fake mediums, publicly exposing their tricks. 

There is no hint of Allen’s signature nebbish character in Firth’s crusty magician; in fact, his Stanley is so full of himself, so arrogant, that the audience naturally roots for someone to take him down a peg. 

Where Allen does seem to insert his real-life persona is in the growing attraction between Firth’s Stanley and Stone’s Sophie. Though their repartee is fun and both actors are skillful enough to make the banter feel natural, there is virtually no sexual chemistry between the two, whose age difference spans more than 25 years. While classic Hollywood romances also had similar age differences, such as Cary Grant and Audrey Hepburn in “Roman Holiday,” the Firth-Stone attraction never feels quite right.

Nevertheless, Stone creates a winsome figure, both cunning and innocent, and McBurney is especially good as Stanley’s friend and fellow magician Howard. Atkins is wonderfully tart and affectionate as the direct Aunt Vanessa. 

Harden, though wasted in a nothing role, does what she can as Sophie’s slippery mother, while Weaver is wonderfully gullible as the wealthy American widow Grace Catledge. Linklater’s insufferably sincere but dimwitted Brice, who’s intent on wooing Sophie by serenading her on his ukulele, comes across as pathetic yet still likable.

Last year, Allen gave us “Blue Jasmine,” a film that not only won Cate Blanchett an Academy Award as best actress but also told a profound story that touched on the Bernie Madoff scandal, personal betrayal, self-deceit and descent into madness. 

This year’s film is much lighter, just pure entertainment set in a lovely time and place. Although only a little bonbon, “Magic in the Moonlight” is still a sweet treat and a welcome grown-up break from the summer’s action films and much duller rom-coms.