A purloined key, handed-off and hidden, then “returned” with dire consequences, bottles of wine whose “vintage” sticker earns a lot of attention, a party’s champagne bucket, emptying steadily and suspensefully and the look of doom in a great actress’s ready-for-my-closeup face, all are pivotal pieces of the brilliant visual puzzle of Alfred Hitchcock’s “Notorious.”

“Psycho” may have the most notoriety in the canon of the Master of Suspense. “Vertigo” remains his flashiest film. And Hitchcock’s other frothy, fast and fun color spectacles of the 1950s — “Rear Window,” “To Catch a Thief” and North by Northwest” — may dominate the ranks of fan favorites among his work.

But “Notorious” is indisputably his masterpiece. It’s built on a sneering, witty and the snare-drum tight script by Oscar-winner Ben Hecht (“Scarface,” “Spellbound”) — one of the best Hitchcock ever adapted. “Notorious” stars two of the enduring legends in motion picture history, Ingrid Bergman and Cary Grant, and earned an Oscar nomination for one of the great character actors of his era, Berman’s “Casablanca” co-star Claude Rains.

It’s a textbook on suspense — how to build it through montage, manipulating the simplest images into edge-of-your-seat excitement and fear for our badly flawed, conflicted heroine. The framing of shots, the production design, even the many obvious rear projection effects that put characters in a careening car or on a street in Rio de Janiero, are all impeccable.

The performances are subtle, the manipulative “love/hate” relationship at its heart utterly believable.

This is the movie to see if you want to find out what all the generations of fuss about Alfred Hitchock have been about. And this is the classic you come back to, again and again, when you consider the decades of failed, passable, good-to-decent and terrific thrillers that followed it.

“Notorious” is everything a romantic thriller should be.

Bergman, costumed to the nines (by Edith Head) and inutterably gorgeous in every shot, is Alicia, daughter of a German-born naturalized American freshly convicted of treason.

It’s 1946, and modern viewers can’t help but note the traitor’s rant about the “next time” he and his kind will try to overthrow America to a judge in the South District Federal courthouse in Miami. No, the judge isn’t female and wasn’t appointed by a traitor. So this time, justice is served.

The beautiful Alicia Huberman is hounded by the press afterwards. She’s an infamous party girl who sets out to drink and party this disaster right out of her life. A mysterious stranger, not a party crasher, just sits quietly and drinks her in. He’s handsome and polished enough to earn her “I LIKE you” without actually doing anything.

Although, one could suppose letting her “I’m liable to blow up the Panama Canal at any moment” wisecrack slide counts for something.

Devlin (Grant) is a rakish and sinister. And when the party’s wound down and she’s talked him into a drunken drive down Florida’s coast, the ticket and arrest she escapes gives away his game. He’s a “cop,” a Fed. And it turns out, he wants her for a “job.”

She’d infiltrate a South American cabal of unrepentent Nazis working for the notoriuous German conglomerate IG Farben. Who knows what they’re up to? It can’t be anything good.

But “patriotism” isn’t enough to turn Alicia into “a stool pigeon.”

“No thank-you. I don’t go for ‘patriotism.'”

Still, the handsome stranger would be her “handler.” OK, then. Maybe she’ll even sober up. For him.

Rains plays the mark, Alex, a rich and connected member of this industrial scale war crime cabal. He was sweet on Alicia, back when her father was free to engage in Nazi activities in an unsuspecting America. She can cozy up to him, get names and find out what these creeps are planning in post-war Brazil and the rest of the Americas.

The script sets up a great clash of wills, with Grant’s Devlin rarely letting us love and concern entering his side of the bargain. Bergman’s Alicia sees through some of his lies, and doubts his attraction.

“This is a very strange love affair.”

“Why?”

“The fact that you don’t love me...”

But once she’s in the middle of all this, with murderous scientists, businessmen and heavies all around her, she clings to Devlin like life itself, reminding him constantly of the risks she’s taking for “love.” He’s still hiding his cards.

“A man doesn’t tell a woman what to do. She tells herself.”

The genius twist to this script is the deft way Hecht — adapting a John Tainter Foote short story — folds in more than one point of view. The spy pokes around, imposes herself in conversations, listens and takes names. The handler reveals his cynicism is a “cover” when he defends her to his boss (Louis Calhern) and superiors.

And then Alex the villain, after courting and then marrying the most beautiful woman in their hemisphere, realizes he’s been rooked. We follow his machinations as he tries to extricate himself from her and the deadly jam she’s put him in.

“We are protected by the enormity of your stupidity, for a time,” is Alex’s mother’s (Leopoldine Konstantin) acidic suggestion of their way “out.”

The suspense Hitchcock mastered in his films of the ’30s becomes excruciating here as we watch the various threads unravel into a deadly finale.

A party with those mysterious vintage wines, that shrinking supply of champagne and a room full of Nazis and Nazi sympathisizers may be the climax.But nothing that follows is anti-climactic.

You listen to the bitter wit of the dialogue, savor the clockword brilliance of the plot and admire the polished perfection of “Notorious” today and it’s hard to take things like “awards season” seriously.

Sure, it was nominated for a couple of Oscars (Hecht and Rains). And sure, it came out the same year as “It’s a Wonderful Life,” “The Yearling,” “Children of Paradise” and “Brief Encounter.”. When none of them could compete with the sentimental, war-just-ended melodrama “The Best Years of Our Lives,” which I’d say is showing its age more than any of those classics, there really is no “justice” in honoring great films.

At least Hitchcock, like Jimmy Stewart (“Wonderful Life”), Jane Wyman (“The Yearling”) and all the other also-rans won the consolation prize. Their films are the classics generations return to, and none of those works are held in higher esteem than “Notorious,” the thriller-lover’s thriller, the Bergman fan’s touchstone and the Cary Grant movie where he kept his cards closest to the chest, making this heroic villain or villainous hero the romantic matinee idol’s greatest dramatic achievement.

Rating: “approved,” TV-14, alcohol abuse

Cast: Ingrid Bergman, Cary Grant, Claude Rains, Leopoldine Konstantin, Ivan Triesault and Louis Calhern.

Credits: Directed by Alfred Hitchcock, scripted by Ben Hecht, based on a short story by John Tainter Foote. An RKO release on Tubi, other streamers

Running time: 1:4