In some ways, the X-Men have always been about family. Looking back to the first Bryan Singer film from 2000, many of the dramatic tensions revolve around a group of outcasts trying to piece together some sort of family unit, centred around the wise and benign Father/Mother Professor X. Sure, there was some squabbling among the siblings, and some love triangles between the older members of the family, but by and large the awkward unit worked: kids were taken care of, educated, nurtured and given a sense of purpose and place. Magneto’s team was also a family in its way, although one must admit that it tilted towards abusive. Things became even clearer in X2, when the difference between a biological and adoptive family was made abundantly clear. (“Have you ever tried… not being a mutant?”) Throughout all the films, one figure lingered on the fringes of the family, never fully committing, but never fully backing out: Wolverine. Which is one reason why it’s so satisfying that in James Mangold’s Logan, his last appearance, Wolverine finally learns how to love and be loved.

Logan is a masterpiece — a truly great American film — but it will mean more to fans that have some history with the characters. It’s 2029 and there have been no mutants born for 25 years. Logan, nihilistic, grumpy and downright suicidal is constantly drinking and working as a limousine driver. An aged Professor X is under his care, living just across the Mexican border, isolated from people as much as possible due to a neurodegenerative disease that causes seizures that send out uncontrolled and ultimately fatal telepathic energy. The medication he takes in order to control his disease has unpleasant side effects, and the Professor is also suffering from mild dementia, so neither of our two main characters is feeling particularly optimistic about their future. Logan is contacted by a strange woman named Gabriela, who has in her care an even stranger little girl named Laura, and she implores him to take them both (or at least the girl) to a haven in North Dakota. It turns out that Laura and Gabriela are also being pursued by a vicious enforcer who works for the Transigen corporation, which has been performing genetic experiments with mutant DNA. At the insistence of Professor X, Logan agrees to take Laura and himself to North Dakota, all the time being chased by the Transigen agents. Thus a classic road trip/chase plot plays out, ending with the inevitable confrontation between Logan and a powerful genetically engineered mutant.

The actual plot of the film may read as pure schlock (even more so if we recall that Transigen is trying to breed a race of mutant super-soldier children), but the tone of the film is absolutely not. This is a serious, emotionally complex, adult take on the superhero genre, and the plot essentially operates as a propulsive force. The true story is of this growly, grumpy, self-loathing reluctant hero being taught how to feel love by a 90-year-old man and an 11-year-old girl. And, yes, there is plenty of startlingly brutal violence and full-on hard-R language. Too much of the discourse around this film has been about those two elements, so we’ll simply mention them in passing here. Yes, it is wonderful to hear Professor X use the word “fuck”, just as, at first, it’s exhilarating to see the consequences of Wolverine’s claw use rendered realistically. But Logan works because of the scenes in between the fights, when Professor X struggles to pull Logan towards the light, to connect him with other people on a human level and to realize that he doesn’t have to be alone in the world.

Patrick Stewart is remarkable as Professor X in this film. Already a knighted, legendary actor, it’s quite astonishing the way the vigorous, muscular 76-year-old Stewart is able to transform himself into a frail old man. All the CG in the world can’t be as evocative and effective as Stewart’s low-tech old-fashioned acting techniques. He’s gentle but firm, confused yet certain of the important things, kind and strong. He hits notes with this character we haven’t seen him hit before, even after 17 years. When the special effects hook into X’s sensibilities, we get haunting, beautiful sequences such as when Professor X has to telepathically calm and gather a group of horses. The visual poetry of that sequence is just as effective as any brutal fight. I’ll happily add my voice to those who have been calling the performance Oscar-worthy.

Not to be outdone, Hugh Jackman also finds new and interesting ways to play Logan himself. We sometimes forget what an acting challenge that character is, and has been. Logan doesn’t have a great deal of emotional range — he’s always seemingly tense and grumpy, mere seconds away from an explosion of rage. But Jackman is able to express grief, pain, frustration, hope and finally love through that narrow emotional filter, without ever betraying the heart of the character or tipping into sentiment. In the hands of a lesser actor, Wolverine’s growly personality would come off as one-note unearned petulance, but Jackman has always made him somehow lovable, never more so than here. This will be his last performance as Wolverine, and it’s impossible to imagine him going out on a higher artistic note.

Logan himself is ultimately tragic and almost Shakespearean, when considered in his totality. Blessed — or cursed — with what amounts to essentially immortality and manipulated and abused for decades because of his gifts, whatever parts of him were once human have long since been almost crushed under the weight of his nihilism and cynicism. He’s justified in his ambivalence about the human race, given how he’s been treated by it, but Professor X from the start recognized that there was still a spark of human kindness in him and spent decades fanning that small flame. It’s only at the end of Logan that Logan finally gives in to what Professor X has been urging him to do for years and feels real emotions.

The metaphor of family works on many levels, but it’s best to consider how it has evolved from a sprawling, energetic and multi-limbed affair in X-Men to a small, simple three-person unit in Logan. With the addition of Laura (played wonderfully by Dafne Keen), Logan realizes that there is the possibility of a better future, and though he might not participate in it, he’s learned enough in his long journey to pass along a bit of wisdom. Laura herself undergoes a similar emotional journey to Logan, from pure rage to pure love, and has the advantage of completing that journey as a child rather than an aged mutant, and thus the future she represents is much more hopeful than the bitter, angry past. For the last part of this film, she essentially serves as Logan’s teacher, and these scenes are never less than convincing, never fall into the “kid sidekick” cliche and pack a tremendous emotional punch.

The impact that Logan has on the way superhero films are made and the way they’re received is going to be significant. Most Marvel superhero films are competently made, entertaining and enjoyable products within a fairly narrow genre filter. Even Captain America: The Winter Soldier or Iron Man 3, which pushed that formula possibly as far as it could go, were still recognizably products of the same creative vision. Deadpool was a fascinating exception, but that film was a self-aware, snarky romantic comedy. Logan, on the other hand, is a truly adult movie that breaks new ground and takes this entire genre to a new level. Marvel has been learning from its films, and though some are better than others, Logan benefits from the accumulation of that collective wisdom. No, this doesn’t mean that all superhero films from now on have to be serious R-rated adult dramas, but it would certainly be nice to get more like this, and for the film to serve as an inspiration for Marvel to take similarly bold, smart risks on future projects.

Great art makes its audience feel emotions — this is hardly an original observation, but that is the best argument for Logan as a legitimate piece of cinematic art. After some consideration, I think it’s safe to say that it’s the greatest superhero film ever made, except perhaps Superman: The Movie, which also succeeds because of its emotional content and smart screenplay. Others will point to The Dark Knight, which is great, no doubt, but that film has never moved me the way Logan did, and I don’t think my experience was unique. This is a film that will be discussed, debated and appreciated for years to come. And the last shot will go down in history as an iconic image of how deeply real this fantasy world can feel.