Alan Rickman, who died on Thursday, at the age of sixty-nine, was a classically trained actor who did time in the Royal Shakespeare Company and made his name in modern theatrical productions, notably "Les Liaisons Dangereuses," which he starred in first in London, in 1985, and then on Broadway, in 1987. Despite being passed over for John Malkovich when that play was turned into the movie "Dangerous Liaisons," Rickman would go on to play dozens of memorable characters onscreen, including Professor Severus Snape in all eight Harry Potter movies, as well as to write and perform for the stage. But, for philistines like me (and, it seems, for many others), Rickman was—and now always will be—Hans Gruber, the toothy, perfectly manicured, sphinxlike villain from the 1988 action movie "Die Hard."

The plot of "Die Hard" barely matters, but quickly: Bruce Willis plays a New York cop visiting his estranged wife at her office in the fictional Nakatomi Plaza, in Los Angeles. Their reunion, during a Christmas party, is spoiled by the arrival of Gruber and his goons, who initially appear to be terrorists, but whose real motive is more simple: money, six hundred and forty million dollars of it. Gruber takes everyone hostage, and only Willis remains at large in the building, left to foil the bad guy's plans.

Enough of that, though. The greatness of "Die Hard," which, in the gun-smoke haze of lousy sequels and terrible knockoffs, has been partly lost, lies in its pacing. We may remember the scenes of frenzied action, and all the broken glass, but, for the most part, the movie is made up of plodding moments of dread-inducing monotony and quiet. Surely no other action movie featured so many characters walking around in anonymous corridors of an office building, humming to themselves. At the center of this is Rickman's Gruber, who is not only a perfect straight man to Willis's catch-phrasing cowboy but also the movie's guiding tonal spirit. He's oddly contained, seemingly bored by the very mayhem he's set in motion. He delivers his first lines to the terrified hostages by reading from a little date book, as if he needs to remind himself which master heist he is scheduled to perform that day.

Gruber has no typical action-baddie backstory—he's not out to avenge his dead brother, or father, or wife, and the best joke of the movie occurs when Gruber gets on the phone with a hostage negotiator and demands the release of various incarcerated political separatists from around the world, members of groups that, he tells his comrade, he simply read about in Time. "Do you think they'll even try to do it?" his henchman asks him. Gruber's response is a kind of personal mission statement: "Who cares?" Indeed, he is simply a blank-canvas thief, one for whom even money seems a little beside the point. He likes nice suits, reads magazines, misquotes Plutarch. No one ever looked so brilliantly uninterested while firing a machine gun or executing a civilian. In Rickman's deadpan performance, Gruber seems to possess a strange fatalism, as if he expects to lose, and to die, all along. Who cares?

But, despite this nihilistic anonymity, it is Gruber who remains the movie's unforgettable character. "Die Hard" made Bruce Willis a movie star, but it earned Rickman a different kind of designation, as the prototypical, and at the same time impossible-to-replicate, action-movie villain. The secret may be that Rickman himself didn't think of Gruber that way. "I'm not playing the villain," he once said. "I'm just playing somebody who wants certain things in life, has made certain choices, and goes after them." What Rickman was describing wasn't a character's backstory—Little Hans in Berlin, unloved and overlooked—but his motivation, distilled down to a human being's most basic urges: see, want, get. Yet from that came a surfeit of specificity: his precise grooming, his distant manner, his slightly nervous yet menacing grin, his flat affect, with a voice that the actor once described as "coming out the back end of a drainpipe." No other action villain had a better beard, a more fun name to say out loud, or a better death scene (involving a stunt that Rickman performed himself, and that, over the years, took on the air of myth, with the distance of his fall growing from twenty to thirty to, eventually, forty feet). Amazingly, Gruber was Rickman's first movie role. He later joked that the producers cast a relative unknown like him because they'd already spent all their money on Willis. But it's impossible to imagine anyone else playing Hans Gruber, and Rickman had the good sense never to play a version of the same role again.

Gruber's cultural immortality was likely helped by the fact that, unlike Willis's, most of his memorable, and quotable, lines survived the censors of basic cable: "I'm going to count to three; there will not be a four”; "He won't be joining us for the rest of his life." My favorite bit is a monologue he delivers over a walkie-talkie to Willis, in an attempt to figure out the identity and nature of his adversary: "You know my name, but who are you? Just another American who saw too many movies as a child? Another orphan of a bankrupt culture who thinks he's John Wayne? Rambo? Marshal Dillon?"

Gruber might have been some Eurotrash snob, but Rickman clearly did not share his character’s distaste for the American audience watching "Die Hard." He was a serious actor, in the best way, which meant that he was serious about this character, bringing to him the same sincerity and empathy—and, with it, a generosity to the audience—that he would to other indelible performances in what might have been silly roles: in the sci-fi farce "Galaxy Quest," or the political satire "Bob Roberts," or the ensemble romantic comedy "Love, Actually," or as Harry Potter's professor of wizardry. In "Die Hard," even among all the gunfire, dialogue about access codes and negotiable bearer bonds, and other eighties-action nonsense, there is a kind of perfect integrity to Hans Gruber. I doubt it's just sentimentality that has so many people on Twitter today declaring that they wish he'd got away with the money.