The Imitation Game is lovely to look at, features two excellent performances and several good ones, and is something of a mess. That’s not all the film’s fault, as Alan Turing’s life doesn’t fall easily into a three-act structure. Turing (Benedict Cumberbatch) was the genius breaker of the WWII Enigma code and developer of the computer. To keep with the British vernacular, it’s a “ripping” story, but the film hasn’t solved the problem of how to cover this complicated life.

Chronologically, Turing’s life—according to the film—goes something like this: He is a young gay boy in boarding school who develops a crush on his sole supportive friend (spoiler alert!) who ends up hurting him by dying. Later, Turing’s brilliance ends up overcoming his social deficiencies and he stumbles into helping at Bletchley Park, the center of code breaking for the British during the Second World War. There he meets the “plebeian” brilliant minds that simply can’t compete with his genius. With the help of Winston Churchill (it’s never really explained), Turing takes over the shop. He fires some, alienates everyone else, and works toward creating what he calls a universal machine—and we would call a computer.

Along the way, he develops an affection for co-worker (and only female code breaker) Joan Clarke, played by Keira Knightley. They get engaged. (More spoiler alerts) Alan breaks it off with Joan because of his sexuality. He genuinely likes her, but more than anything wants her to stay and help. The team eventually breaks the code, a feat that must be kept secret to be effective, even it if means lost lives in the process.

At the end of the war, they must all be sworn to secrecy, i.e., they have never met one another and haven’t worked at Bletchley Park, etc. As Cold War fears arise, an investigation into Turing’s alleged political proclivities stumbles onto his then illegal sexual activities, and he is arrested. He chooses what he believes is the lesser of two evils in terms of punishment, and eventually comes to a sad end.

What do you do with all that? Well, the filmmakers have chosen to make a framing device of the investigation of Turing’s politics that turns into an accidental discovery of illegal sexual activities. It’s the weakest part of this film dramatically (something that happens accidentally to a third party) and doesn’t adequately support the rest of the film. Then they move us around from Turing schoolboy years (to explain or at least demonstrate his sexual preferences?) to the exciting war years to the police investigations. The pace doesn’t move fast enough to “whip us around,” so we don’t get dizzy. But we don’t have a clear story to latch onto. Is this a biopic? Is this something like Lincoln or Selma, where we focus on a great man’s life by slicing out a piece of it to examine? Or is it ultimately a sociopolitical statement about the treatment of gays, whether in 1950s Britain or now? Turing’s life doesn’t make it easily, but the film can’t make up its mind.

What we do have, though, is a couple of performances to enjoy and admire. Thank God for Benedict Cumberbatch, who is finally getting the attention and respect he deserves. Yes, he’s amazing as Sherlock. But he was also amazing in 12 Years a Slave, and odious in Atonement, and terrific as Smaug in the Hobbit films, and touching in August: Osage County. He’s an actor’s actor who’s broken out and become not only popular, but a staple of popular culture (which seems, thankfully, not to have affected his work). For those few who are not familiar with him, you won’t know him by his work here in The Imitation Game. As Turing, he has a posture, accent and way of getting his words out that is different from anything he’s done before. Sherlock he ain’t.

Just creating a character like Turing is accomplishment enough. It includes intellectual brilliance, social cluelessness that’s not cute or endearing, and as the New York Times’ A. O. Scott puts it, “[Cumberbatch’s] curious ability to suggest cold detachment and acute sensitivity at the same time.” Then watching this character go through the paces that Turing’s life threw him is something else. The focus, the work, the rejection, the trials of leadership, the isolation of genius, the struggle with being so very different in so many ways, and the physical challenges of the last few years of his life—these experiences are what makes this performance such a joy to watch, and what will make this film worth viewing more than once.

Nearly as good as Cumberbatch is Keira Knightley, who proved nearly a decade ago in Pride and Prejudice that she was more than a star, but an actress capable of variety and depth. She proves it once more here with a part another actress might have settled into nicely (or sailed through). Knightley brings her usual spark and charm, but creates a real, intelligent, full-blooded character who grows up emotionally in front of our eyes (but only if we’re really looking). It’s a great reminder of what she can do, and brings some exciting anticipation to a career that seemed to have artistically plateaued.

The rest of the cast is solid and typically British-excellent. Downtown Abbey’s Allen Leech (Branson, the Irish driver who married Sybil) makes an easy transition into film in what is a bigger part than it seems at first. Charles Dance (Game of Thrones, Bleak House) as Commander Denniston, however, is in slight danger of becoming the go-to moustache twirler of entitled British bad guys. He needs a comedy or romance in his résumé, stat.

The two lead performances hold this film together, but otherwise, The Imitation Game doesn’t add up to the sum of its many, many parts. Perhaps it is a sign of our times that the film had the multiple focuses it had, and that it couldn’t have presented Turing’s life—or even part of it—in any other way. Over time, the performances will be what will be remembered, and the rest of us academicians can study what other alternatives to the story might have worked better for the film.