I Am Love, Italian auteur Luca Guadagnino's 2009 collaboration with Tilda Swinton, swirled in elegantly melodramatic fashion around a couture-clad matriarch slowly unraveling from the inside out. A Bigger Splash, which has nothing to do with the minimalist David Hockney painting of the same name, finds him just as obsessed with attractive surfaces, but everything else has changed (he swiped the scenario from 1969's erotic thriller La Piscine with Alain Delon and Romy Schneider).

In her third go-round with the director, Swinton plays Marianne, a David Bowie–esque rock star on holiday with her photographer partner, Paul (Belgian brooder Matthias Schoenaerts in destabilizing Rust and Bone mode). It's the height of summer on the Sicilian coast, and waves of heat undulate through the air. Marianne and Paul are having a fabulous time sunbathing in the nude and fucking in the pool when they receive an unexpected visit from boisterous, coked-up record producer Harry (Ralph Fiennes), Marianne's former flame, and his sullen, peroxide-blonde daughter Penelope (a very game Dakota Johnson), whom he's only just met.

Instead of the rat-a-tat performances she's given in fast-moving films like Hail, Caesar! and Michael Clayton (for which she won the best supporting actress Oscar), Swinton is mostly mute since Marianne is recovering from throat surgery, and may never sing again, so Harry does most of the talking, spinning tales about his innovative production work for the Rolling Stones and the time he introduced Paul to Marianne. He predicted they would hit it off, and he was right, but now he wants her back, and so his campaign begins. First, he tries to dazzle her with his charm (it is considerable) and his moves (his Zorba the Greek–like dance to "Emotional Rescue" is one for the ages), and when that fails, he attempts to break the insecure, defensive Paul, a recovering alcoholic whose documentary-making career is stuck in neutral.

Though they hail from different countries and different schools of acting, the cast jells as if they've been living on this beautiful but dangerous island for years—there are snakes in the grass and refugees roaming the hills—but Fiennes gets all the show-stopping moments (it doesn't hurt that he and Swinton previously worked together on The Grand Budapest Hotel). In an about-face from the tightly wound roles that defined his early career, like the sadistic Amon Goeth in Schindler's List, Fiennes is funny and sexy and ultimately pathetic as an aging lothario confronting the limits of pleasure and privilege. The film belongs to him, and he's magnificent.