Dear Avery,

You wouldn't think it, but there's a rich cinematic history of shark-chumming. Most famously, Roy Scheider at the stern of the Orca, scooping blood and guts into the ocean (and, most infamously, Samuel L. Jackson chumming the air with motivational rhetoric). But, unlike Jaws and Deep Blue Sea, the new flick for which you chummed, All is Lost, isn't a shark flick. The danger, here, is a bit more abstract.

At first glance it might seem, with its nautical themes and everyman-against-the-odds plotline, is the Volcano-versus-Dante's Peak companion piece to the fall's other seafaring thriller, Captain Phillips. But the current film to which it bears a much more striking resemblance is Gravity. Like Alfonso Cuaron's outer-space amusement park ride, nature is the antagonist--though in_ All is Lost _it's not an absence of physical force against which our cast-adrift hero struggles, rather a preponderance of it.

And, yes, that physical force takes form, eventually, in a school of circling sharks. Which I suppose we can thank you for inviting to the party with your skillful dissemination of chopped-up fish entrails.

It's a random accident that first puts our nameless hero in peril. A stray cargo container collides with his sloop in the Indian Ocean, spilling running shoes into the sea (chum for sneakerheads) and punching a hole in the hull. It escalates from there, as storms, more storms, and even worse storms beset the aging sailor. He relies on every maritime trick imaginable to keep his yacht afloat, and for a while succeeds--but, as it is in this sort of survival film, he is eventually pushed to the brink, and it's there that we first meet your friends, those sleek underwater killing machines.

I think it's telling, though, that the menace the sharks present is far less immediate than the misplaced lid of a water jug. This is a movie about details. About knot-tying and droplets of fiberglass resin. About making sure you're clean-shaven before facing death. The presence of sharks feels like too obvious a hazard; a moment of jeopardy too easily conjured in a film that seems to pride itself in finding jeopardy in unlikely places.

That Robert Redford plays this aging sailor must have been quite the experience. He was out there on the water with you--did he help you chuck some chum? Toss a few handfuls of bloody viscera? He seems like the type. His character, too. The coolness with which he meets that first misfortune seems almost callous; but it's that same coolness that makes the man-versus-nature conflict seem evenly matched.

We never learn anything more about Redford's character than what is revealed by his actions and demeanor. Much is being made about the lack of dialogue in the movie, and, sure, we only hear Redford speak two or three times, but it's not a quiet performance. He still has that old-school movie star presence, and knows how to use it sparingly.

This restraint is pretty admirable. Where other films (Gravity among them) misjudge the audience's affections (and attention-span), this flick's director, J.C. Chandor, knows that there's nothing more essential, more primal, than a man's will to live. The stakes can't get any higher; no saccharine backstory about dead children is required.

Late in the film, after things have gone from bad to worse to hopeless, Redford opens up a decorative wooden case. Inside is an antique sextant. And a greeting card. Clearly the instrument - now vital to his survival - was a gift. Redford hesitates a moment, seems about to open the card and read it, but stops himself, tosses it aside, and gets on with the business of celestial navigation.

Whatever maudlin message he might have found inside that envelope stays there. Chandor doesn't need to bloody the water with sentimentality to make us care. He earns it the old-fashioned way.