Avengers: Infinity War capstones a decade of world-building across 18 movies, ten television shows, and two Hulks, but the most ambitious crossover event in (cinematic) history ultimately comes down to the bartering of six magical gems. The Infinity Stones, varying in power, name, and color, are the currency of the entire Marvel Cinematic Universe. For Thanos, the mad Titan, the stones will buy closure—he’s been committing genocide for a long time. For the Avengers, the stones buy continuity—“you can’t be a friendly neighborhood Spider-Man without a neighborhood,” explains Peter Parker. Moviegoers have learned to refer to objects like the Infinity Stones as MacGuffins and to treat them with suspicion or scorn, and it’s hard not to empathize. The tesseract of Captain America: The First Avenger, for instance, didn’t make the Nazis more evil. Nor did the scary “hole” of The Defenders make their alliance feel less contrived. But MacGuffins aren’t all empty holes. Infinity War proves that with the right objects and characters in pursuit, MacGuffins can have real meaning.

MacGuffins are shorthand for objects that exist to propel the plot. The Harry Potter series has Horcruxes and the Philosopher’s Stone; Pulp Fiction uses a glowing suitcase; Moana features a magical heart. Alfred Hitchcock described MacGuffins as “a name given to this kind of thing such as stealing ‘the papers.’ And really they don’t matter. The plausibles and the logicians are always looking for the truth in the MacGuffin, in the papers, or the plans, or the fort or whatever. My contention has always been that although for the characters in the story they are most vital, for me, the teller of the story, they are absolutely nothing.”In modern usage, MacGuffin implies that an object in a film is arbitrary or uninventive, but Hitchcock used it to note his personal disinterest in symbols with fixed meanings. As a director, his goal was to translate a character’s fixation on the MacGuffin, as well as their will to obtain it, into compelling cinema. For genre fare involving espionage, crime, and heists, or deep character studies (all of which were Hitchcock’s bread and butter), ‘MacGuffin’ signaled that the characters and their motives were the real vehicle of the storytelling rather than the plots, which were often repetitive. Through a MacGuffin, a story can be fueled by pure desire—obsession, revenge, greed, will—even if the object in question has no underlying value. MacGuffins convert desire into narrative. In Avengers: Infinity War, we see Thanos’s shadowy desire for the Infinity Stones, a plot that was introduced in 2012’s The Avengers, finally become the main story. The Infinity Stones have frequently changed hands across all these movies, and those various exchanges undergird how the characters of Infinity War conceive of themselves and their purpose. For Doctor Strange, for example, the Time Stone embodies his commitment to protection; it elevates him from sorcerer and is instrumental in his unlikely defeat of Dormammu. For Loki, the Space Stone, which he pilfered in Thor: Ragnarok, gives him yet another chance to one-up Thor. The Mind Stone lodged in Vision’s forehead makes him sentient, which in turn affects his relationship with Iron Man: Tony Stark respects Vision’s wish to live independently because Vision embodies his past abuses of technology. The Infinity Stones could easily be “Infinity Bracelets” or “rings,” and their goofy name certainly doesn’t hide their comic book origins, but their value is ultimately relational. They become significant through the mechanisms in which they are lost, gained, and used. Calling them MacGuffins obscures how this value works. As the focal point of Infinity War, Thanos makes all these transactions explicit. In his various encounters with the Avengers, he essentially haggles his way into galactic power. From his initial encounter with Thor and Loki in deep space, to the showdown on Titan, to the standoff with the Guardians of the Galaxy on Knowhere, Thanos boils conflicts down to transactions: a life for a stone. It’s a terrible deal, and that’s the point: Each stone embodies some hero’s commitment to preserving the lives of friends and strangers, a task that’s complicated by making death a bargaining chip. With each successful negotiation—and its shimmering haul—Thanos is able to show how feebly the heroes grasp what they’re up against. Each of his victories could be avoided by one small sacrifice, but the heroes refuse to compromise, furthering Thanos’s quest. It’s a clever inverse of the superhero triumphing through perseverance.

Meanwhile, Thanos has been pursuing the Infinity Stones behind the scenes for years, so it’s a feat to see him inflate their value from battle to battle. In the lead-up to his fatal finishing move, we have a front row seat as Thanos traverses worlds and galaxies and battlefields just to make himself a martyr for a cause he has convinced himself is right. We see him toss a moon and beat the Hulk into hiding and torture his daughters solely because of his own neuroses, never considering what the universe might become if he fostered life rather than snuffed it. In one movie, he goes from manipulating the Marvel Cinematic Universe to controlling it.

The Infinity Stones are more than just plot devices in this context; they make this takeover clear and translate its varying impacts on the sprawling Avengers lineup. When Thanos tortures Nebula to extort Gamora’s knowledge of the soul gem, the sisters’ already fraught relationship is wound tighter. When he tells Iron Man, “I hope they remember you,” he diminishes the Avengers’ accomplishments and mocks Iron Man’s wearying journey from a cave in Afghanistan to the depths of space. You don’t have to know how the time, space, soul, power, mind, and Reality Stone work to comprehend that Thanos shouldn’t wield them. But by focusing on the maniac beneath the lavender rind and the craggy skin beard, Infinity War is able to route 18 movies worth of victories and losses, lessons and follies, jokes and gags, through one being’s corrupting will. Thanos is a gravity well of ego and malice. The Infinity Stones are the spoils of his great bargain and emblems of his astounding arrogance, the entirety of the universe reduced to one man’s relationship with his left hand.

Hitchcock dismissed MacGuffins because they were irrelevant to his particular creative interests. He was more focused on telling the story, not explaining it. This doesn’t make energon or mother boxes or crystal skulls any less goofy, but MacGuffin is just a cruder word for symbol. In the right context, any symbol can accrue or lose value. The MacGuffins, in their way, mean absolutely everything. Avengers: Infinity War compensates a decade’s worth of narrative investment. Put some respect on those stones.