Fiennes, Swinton simmer and boil in ‘A Bigger Splash’

A craggy, stormy volcanic island off Sicily. Some fabulous real estate. A little food porn. Tilda Swinton’s face, and Ralph Fiennes’ — well, a lot more than his face.

What more could a film buff want?

To be fair, “A Bigger Splash,” by director Luca Guadagnino, has an uneven feel. For 90 minutes it floats along as a relaxed exploration of four quirky characters — attractive, lustful, bored, somewhat confused — and the shifting ties that bind them, carnally and otherwise. Then, suddenly and shockingly, it turns into a psychological thriller for the last half-hour. It’s a shift in tone that feels uneasy and a little forced.

But by then, you’ve been lulled into a second-glass-of-wine feeling — perhaps a result of watching those lazy, al fresco meals overlooking the sea. Your defenses are down, and you’re ready to flow with it until the end, even though you have a feeling you’re going to be left a little unsatisfied.

The setting is the Sicilian island of Pantelleria near Tunisia, where Marianne (Swinton) and her boyfriend of six years, Paul (Matthias Schoenaerts) are staying in a sprawling home atop rocky cliffs, with a nice swimming pool (the film is a reworking of the French New Wave classic “La Piscine,” which should give aforementioned film buffs a sense of where things are headed).

Marianne is a rock star not unlike David Bowie — a role that fits the pale, androgynous, chameleonlike Swinton to a T — who is recovering from vocal cord surgery and not allowed to speak. This means that for most of the film, Swinton lacks one of an actor’s chief instruments: the voice. This challenge also suits Swinton to a T; in fact, it was her own idea to render Marianne virtually speechless, jettisoning dialogue originally planned for her.

Boyfriend Paul is a rather brooding, hunky, protective type with his own troubled past, and the two are enjoying a fairly idyllic period of mutual recovery — nice meals, afternoons in the nude by the pool — when the phone rings. It’s Harry (Fiennes), a gregarious record producer and Marianne’s former flame, arriving unexpectedly on the island. As if his uninvited visit isn’t enough, Harry’s brought along a surprise: a 20-ish daughter, Penelope (Dakota Johnson), whom he’s only recently met.

Fiennes is uninhibited, both physically and emotionally, and quite riveting as Harry, a man burning with unresolved appetite.

Watch him sing sexy karaoke with Penelope — yep, sexy karaoke with his daughter. Watch him try to woo Marianne back with the help of some warm, freshly made ricotta cheese (this is the aforementioned food porn.) And finally, watch Fiennes dance rapturously to the Stones’ “Emotional Rescue.” It’s a cliche, but we’ll say it: It’s worth the price of admission.