Perky music and a suave, light-footed entrance by Kevin Kline as an American in Paris give the early scenes of “My Old Lady” the feel of a Franco-American comedy in the vein of Cédric Klapisch’s recent “Chinese Puzzle.” But the 75-year-old playwright Israel Horovitz’s screen adaptation of his own 2002 production is not what it initially appears to be.  Mr. Kline brings his characteristic lilt and twinkle to the role of Mathias Gold, a failed playwright in his late 50s who is a three-time divorcé and a recovering alcoholic near the end of his rope. He has traveled from New York to Paris to claim his only asset, a splendid apartment in the Marais willed to him by his estranged father.  Upon arrival, he is shocked to discover a tenant, Mathilde Girard (Maggie Smith), who has occupied the premises for decades. He soon learns that an old French law precludes him from selling the property to a developer while Mathilde is still alive. In the meantime, Mathias, who is nearly penniless, must make monthly rental payments to Mathilde or lose his claim to the apartment.  Mathilde is a vigorous, strong-willed Englishwoman in her 90s who shows few signs of decrepitude. Living with Mathilde is her glum, sour daughter, Chloé (Kristin Scott Thomas), whose reaction to Mathias is one of instant loathing. No actor can turn a colder shoulder than Ms. Scott Thomas in her icy mode, and Chloé’s bitterness sends a warning chill through a movie that metamorphoses from a real estate comedy into the fraught drama of secretly interwoven family histories.  After researching French inheritance and property laws and meeting with a developer, Mathias tries to strike a deal with Mathilde to share the property, but she refuses. She finally agrees to let him stay in a spare room until he makes up his mind about what to do. As the three become acquainted, the film’s tone darkens, and Mr. Kline brings his Shakespearean expertise to Mathias’s anguished soliloquizing about his troubled family and his father’s negligence.  Those hoping to see Ms. Smith create a variation of Violet Crawley, the haughty character she plays in “Downton Abbey,” may be disappointed that Mathilde has none of the blustery camp mannerisms that make Violet, the dowager countess, a lovable über-snob. For a woman in her 90s, Mathilde has a rich, active life. She teaches English to French students in private classes and has a well-stocked wine cellar. The stress of Mathias’s circumstances drives him back to the bottle, and his outbursts suggest Falstaffian rants by a character out of Chekhov. Even when behaving like a jerk, Mr. Kline’s Mathias is unfailingly charming.  Ms. Scott Thomas makes the most of her problematic character, a woman whose frozen facade melts suddenly and unconvincingly into mush when Mathilde spills decades-old secrets that reveal her to have been as selfish and irresponsible as Mathias’s father.  As the truth tumbles out, the dialogue and the carefully timed revelations make “My Old Lady” seem increasingly stagy. But the performances go a long way toward camouflaging the screenplay’s clunky mechanics. Mr. Kline’s performance, in particular, infuses a story of father-son strife with emotional heat.  “My Old Lady” is rated PG-13 (Parents strongly cautioned) for some sexual references.  Written and directed by Israel Horovitz; based on Mr. Horovitz’s play; director of photography, Michel Amathieu; edited by Stephanie Ahn and Jacob Craycroft; music by Mark Orton; production design by Pierre-François Limbosch; produced by David C. Barrot, Nitsa Benchetrit, Gary Foster, Full Dawa and Rachael Horovitz; released by Cohen Media Group. Running time: 1 hour 47 minutes.  WITH: Kevin Kline (Mathias Gold), Maggie Smith (Mathilde Girard), Kristin Scott Thomas (Chloé Girard), Dominique Pinon (August Lefebvre), Noémie Lvovsky (Dr. Florence Horowitz) and Stéphane Freiss (François Roy).  A version of this review appears in print on September 10, 2014, on page C6 of the New York edition with the headline: An Apartment in the Marais, With Complications and Family Secrets. Order Reprints|Today's Paper|Subscribe
In “My Old Lady,” a failed American playwright inherits a splendid Paris apartment, but French law gives his tenant the upper hand.