Robert Redford has long been one of our greatest movie stars. He's never been one of our greatest actors. For every compelling performance he gives, as in Butch Cassidy and the Sundance Kid (1969); or All the President's Men (1976), he gives several bordering on narcolepsy.

Just look at him in The Company You Keep (2013). This is a man on the run from federal agents—a man who may have murdered a bank teller as part of a Weather Underground-type movement—whose heart rate doesn't get above 45 beats per minute, and not because he's filled with anguished resolve.

In All is Lost Redford is the whole show, and the fate of the movie rests squarely on him. It doesn't matter how good a screenplay is (and J.C. Chandor's screenplay and direction are excellent) if we don't care about the person on screen.

Redford is up to the challenge. In All is Lost, he's quick, canny, resilient, angry and morose, all in the span of 100 minutes, and often in the same scene. All is Lost is beautiful, wonderfully acted, terrifying and altogether possible.

An unnamed man (Redford) on a solo voyage in the Indian Ocean wakes up to the sound of rushing water as his boat collides with a shipping container adrift at sea. The hole in the hull rapidly fills with water—and children's sneakers, a sly commentary on the global reach of Western commerce, and becomes the least of the man's problems.

In fact, he's so quick thinking, he patches the hole in about 24 hours with plastic grabbed from other parts of the boat and a heavy-duty epoxy. Unfortunately, the damage from the shipping container is the least of his problems. His navigation equipment, which rests directly under the hole, is waterlogged and useless. Even drying the equipment out on deck doesn't help.

He makes the most of books on board that detail celestial navigation and figures he's about 1200 miles south of the nearest shipping lane. Soon he plots a course to sail toward it.

Nature has other ideas. There are approaching storms, big storms, and it's here that Redford (the character doesn't get a name—and does he really need one?) runs into the worst trouble. The boat is tossed around in waves so big they're actually difficult to see; the ocean just looks like a wall of water, and the boat may as well be a toy. And then there's the driving rain and gusting winds to contend with.

Director Chandor's first feature was Margin Call, the 2011 drama about an investment bank on the verge of going under during the 2008 financial crisis. Lots of talking with stern voices and veiled threats about the end of life as we know it.

All is Lost is a wholly different animal, no less dangerous, and answers similar questions: What are we made of? What are the lengths we will go to survive? At what point do we give up?

On paper, those questions seem quaint, or even a little trite. On screen, with millions of gallons of seawater rushing toward a 39-foot yacht, they become tangible and scary. Imagine surviving one capsizing, and then another, and then knowing that your nightmare isn't over.

All is Lost is one of the best films of 2013, and Redford's performance is certainly his greatest. Alongside Chiwetel Ejiofor and Michael Fassbender in Steve McQueen's 12 Years a Slave, look for Redford on every acting shortlist at year's end. What he does with a steely glance or a hopeful look speaks louder than his opening voice-over (the film's one misstep) and reminds us why he's been one of the most fascinating figures in cinema for nearly 50 years.

ALL IS LOST
Directed by JC Chandor
Starring Robert Redford
The Screen
107 min.
PG-13