“Old” is a fiendish idea only partially realized. What if you only had one day to live your life instead of decades? What if you had to watch your spouse and, even worse, your children age and wither before your eyes? “Stop wasting this moment!” a mother admonishes her young son and daughter in the film’s opening scene, and, brother, they don’t know the half of it.
The puppetmaster pulling the strings in “Old” is its writer-director, M. Night Shyamalan, who here returns to the kind of “Twilight Zone” bear trap in which he specialized before his career went off the rails in the early aughts. The movies he made after his breakthrough with “The Sixth Sense” (1999) may have received mixed reviews, but “The Village,” “Signs,” and “Unbreakable” have an undeniable craft and lunatic conviction that, two decades on, hold up. (Less so for “Lady in the Water” and “The Happening.”) “Old” is a return to that eerie if conceptually and dramatically wobbly form.
A family arrives at an upscale tropical resort in an unnamed foreign country: Mother (Vicky Krieps of “Phantom Thread”), father (Gael García Bernal), 11-year-old daughter (Alexa Swinton), and 6-year-old son (Nolan River). On their first day, the resort manager (Gustaf Hammarsten) recommends an isolated beach and arranges for the family to be driven there along with a few other tourists, including an officious doctor (Rufus Sewell) and his family.
The mother, Prisca, and father, Guy, are having their difficulties — arguments in loud whispers that the kids can’t help hearing — but that pales as the morning lengthens and strange things start to happen. A body washes ashore and decomposes within minutes. The children start complaining that their bathing suits are too tight. Then a lapdog belonging to the doctor’s mother (Kathleen Chalfant) dies. Then the doctor’s mother dies.
Because it’s an M. Night Shyamalan movie, there’s no explanation for why the beach has the ability to rapidly age the human body — until the very end, when there’s an explanation that’s both ridiculous and ridiculously satisfying (again, think “Twilight Zone”). It’s the middle sections of “Old” that lose their grip as the characters are losing theirs, the camerawork going wonky as tempers rise and despair kicks in. Many of the characters, it turns out, have a major health issue of one sort or another. (Is that why someone seems to be watching them from a distant mountain ridge?) One of the characters, it turns out, is in the midst of a psychotic breakdown, bad timing for everyone else but good for raising the movie’s pulse.
Things happen fast in “Old” — a pregnancy gets compressed from nine months into 45 minutes, and a tumor swells from a golf ball to a cantaloupe. The latter requires emergency beachfront surgery, especially difficult when an incision heals as soon as it’s made. Shyamalan piles on the events and improbabilities, some of which are ludicrous: The ultimate fate of the doctor’s neurotic trophy wife (Abbey Lee) is out of a B-movie. And, surprisingly, the physical transformations of the older characters just aren’t terribly convincing.
The kids have it easier, growing up to be played by different actors. Alex Wolff (“Pig”) and Thomasin McKenzie (“Leave No Trace”) are the teenage brother and sister, replaced by Emun Elliott and Embeth Davidtz (“Big Fish”) as adult versions moving into middle age, and it’s with the last two that a more existential tragedy finally surfaces in “Old,” one that’s relevant to the lives still streaming by once the movie ends. It goes fast. It all goes so fast. Don’t waste this moment.
Written and directed by M. Night Shyamalan. Starring Gael García Bernal, Vicky Krieps, Thomasin McKenzie, Alex Wolff, Rufus Sewell. At Boston theaters, Coolidge Corner, suburbs. 108 minutes. PG-13 (strong violence, disturbing images, suggestive content, partial nudity, brief strong language).