'Sisu' asks: What's more fun than watching a grizzled old guy mow down Nazis?

Sometimes it’s rewarding to watch a challenging movie like “Beau Is Afraid,” which requires you to try to figure out what is going on from literally its first frame.

And sometimes it’s an absolute blast to just sit back, turn off your brain for an hour and a half and watch an old guy take out a small army of Nazis with a pickax and grim determination.

So it is with “Sisu,” Jalmari Helander’s outrageous — and outrageously fun — film. It spills blood like it was beer at a bachelor party, but with enough of a wink and a nod to assure us that Helander isn’t taking the whole thing so seriously that we can’t laugh a little.

Or a lot.

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What does 'sisu' mean in English?

The film begins with on-screen text telling us that “sisu” is a Finnish word for which there is no direct translation. Yes, the no-translation bit is often a copout to add a little artificial intrigue, but it’s not a fatal flaw here. The loose meaning is white-knuckled courage in the face of overwhelming odds. Invincibility seems to play a role, as well — maybe even immortality.

This context will come in handy. We meet Aatami Korpi (Jorma Tommila), for whom the word “grizzled” could have been invented, as he and his horse and dog look for gold in northern Finland. It’s 1944, and the war is all but over. Desperate Nazis are in retreat, and burning, looting and pillaging everything in their path.

Aatami is an old soldier, we learn, but has left war behind. Or so he thought. As he digs fruitlessly the sounds of battle inch closer and closer. He blithely ignores a squadron of fighter planes that soar overhead.

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Here's what triggers the bloodbath in 'Sisu'

Then one day he strikes gold, and lots of it. He packs it into bags and heads to civilization. Except he is met by Nazis along the way. They have kidnapped several young women and seem gleeful in their evil.

At first they let Aatami pass, but eventually figure out what he has in his saddlebags. They take some of his gold.

And then he kills them. Brutally. Knife-through-the-skull kind of thing. Aatami escapes, and Bruno (Aksel Hennie), the SS officer leading the Nazis, gets word from headquarters that they are not to pursue Aatami. Did you tell them he killed seven of our men, Bruno asks the radio operator?

Yes, he says. They say we were lucky.

Meanwhile Aino (Mimosa Willamo), one of the captured women, explains to the Nazis who Aatami really is: a former soldier who killed 300 Russians after they murdered his family. He will not stop, at any cost, to get revenge.

Is he immortal, a soldier asks? No. He just refuses to die.

It’s not for lack of trying on the part of Bruno and his henchman Wolf (Jack Doolan). Bruno sees a path to buy his way out of postwar prosecution and so ignores orders, continuing to chase Aatami.

As the Grail Knight says in “Indiana Jones and the Last Crusade,” he chose … poorly.

Hardly any dialog: Aatami does his talking with his pickax

Aatami is relentless. He takes punches. He gets blown up. He hangs with his pickax from a plane in flight. And still he fights on.

Tommila plays Aatami as the strong, silent type — so silent that he doesn’t speak until there’s about a minute left in the film. He does his talking with his fists. And his knife. And, of course, his pickax. There is a great scene in which he is taking his time with one Nazi when a couple more pull up on motorcycle.

That’s him, they say, and stare. Aatami merely looks at them, points his pickax like the Grim Reaper with his scythe and grunts. The two drop their guns and flee.

Aino seems to have a little sisu in her, as well; Willamo is compelling in brief appearances.

The violence is gory enough to make the audience squirm, and just cartoonish enough to give it permission to laugh. Like the “John Wick” movies, it’s really one brutal set piece after another, though the choreography is not as poetic here.

It is fun, though, and fully nuts. In case there was any question, that’s a compliment.

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'Sisu' 3.5 stars

Great ★★★★★ Good ★★★★

Fair ★★★ Bad ★★ Bomb ★

Director: Jalmari Helander.

Cast: Jorma Tommila, Aksel Hennie, Mimosa Willamo.

Rating: R for strong bloody violence, gore and language.

How to watch: In theaters Friday, April 28.

Reach Goodykoontz at bill.goodykoontz@arizonarepublic.com. Follow him on Facebook @GoodyOnFilm and on Twitter @goodyk. Subscribe to the weekly movies newsletter.

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This article originally appeared on Arizona Republic: 'Sisu' review: Nazi-killing World War II film is a gory good time