Warning: Major spoilers for Star Trek Into Darkness follow.

By all rights, Star Trek Into Darkness should be a really good movie. The acting is superb. The core cast established themselves as a force to be reckoned with in 2009, and they've only gotten better. The racial politics of casting a British guy as an Indian man originally played by a Mexican actor are dubious as hell, but there's no question that Benedict Cumberbatch's performance is spectacular.

If only he’d had room to work.

Unfortunately, Into Darkness is wrestling with way, way too much story for one movie. The latest installment of the Trek franchise mashes together the Original Series episode "Space Seed," which introduces Khan and establishes the foundations of his later eponymous fury, *The Wrath of Khan *minus the Genesis plot, and a dash of the political machinations from The Undiscovered Country. That's a lot of ground to cover in two hours, and the whole movie suffers for it. The pacing is choppy and weird, racing past plot holes and lingering on brutal hand-to-hand combat drawn out so far past the point of feasibility that it actually gets boring.

But the problem isn't that Darkness tried to pull together a single coherent story using pieces from previous Trek incarnations. The problem is that it pulled almost arbitrarily from each, a Mad-Lib of allusions with no real attention to the underlying machinery that makes them tick. It's the Silent Hill: Homecoming of Trek film: loads of potential that falls short because in the rush to recreate the window dressings, no one noticed the actual, substantial structure that originally supported them. The result is a mishmash of story fragments that don't really fit together, dubious causality, a plot driven by crises that never quite stand up to scrutiny–and, of course, Carol Marcus.

Alice Eve as Carol Marcus in Star Trek Into Darkness

Let's take a minute to talk about Dr. Carol Marcus. In The Wrath of Khan, Carol Marcus was a molecular biologist and Kirk's old flame. With her son and colleague David, Marcus had developed the Genesis Device—the technology that propels the plots of both Khan and The Search for Spock. While she doesn't do that much in the film—Project Genesis and its staff are mostly collateral damage in Khan's quest for vengeance—she's smart, resourceful, and no one's damsel in distress. Even before we meet her, Carol is established as a force to be reckoned with, both as a scientist and as the girl who broke Kirk's heart (and no, she doesn't regret it or take him back or die).

Carol Marcus of Into Darkness? Not so much. She's a general's daughter who snuck onto the ship for nebulous reasons and has all the personality of a houseplant. She doesn't do anything except get used—unsuccessfully—as a bargaining chip. Her vaunted expertise proves nigh useless, because, ladies, we all know that real validation comes with a lingering glimpse from Kirk (and a longer one from the camera) as you strip down to your underwear on a shuttle in a scene that's obviously supposed to be saucy and charming, but mostly just ends up stupid and awkward and sad. (And, as even Star Trek Into Darkness writer Damon Lindelof admitted yesterday, totally gratuitous.)

And that's a full half of the female characters with names, right there.

Uhura remains a badass, but unfortunately she's been overcome with a case of Generic Lady Motivation. Specifically, Not Being Able to Shut Up About Relationship Stuff. Y'all, Nyota Uhura is a highly professional officer who has thus far made a point of keeping her personal relationships the hell out of her job and took Spock to task the one time he failed to do the same. If you think I'm going to believe that she's going to go off on her Vulcan boyfriend/first officer for not showing his feelings in the middle of a dangerous away mission with their mutual boss, then you are *sorely *mistaken.

Screenshot: Twitter

Once you start looking at the source material, you open the floodgates. Abrams has faced criticism from the start for how far he's militarized Trek, and, in doing so, lost the original's spirit of exploration, of solving problems by out-thinking them rather than outgunning them. Early in Into Darkness, there's a moment that's either the most or the least self-aware bit of writing in the movie, when Scotty seems to channel disgruntled Trek fans as he demands of Kirk, "This is clearly a military operation. Is that what we are now? 'Cause I thought we were explorers."

Me, too, Scotty. Me, too.

But what I keep coming back to is Khan.

Look, I didn’t set out to directly compare Into Darkness and The Wrath of Khan. I really didn’t. Even when I found out Khan was part of the basis for Darkness, I decided not to re-watch it in the months leading up to Into Darkness's release. I was determined to take Into Darkness on its own merits without the tint of nostalgia.

Except, Into Darkness really, really wants you to think about The Wrath of Khan. It's loaded with references—many overt, more oblique. The parallels it builds and reinforces are deliberate and, if you're even passingly familiar with Khan, impossible to miss. That kind of concentrated nostalgia is a dangerous card to play, especially when you're referring back to something that's both beloved and well-wrought; inviting comparisons is really only something you want to do if you're sure they'll work out in your movie's favor.

There's a line from Mystery Science Theater: 3000 that applies here: "Don't put a good movie in the middle of your crappy one." Or, in this case, don't painstakingly reference and build parallels to it, because, even if you set nostalgia aside, there is no universe in which The Wrath of Khan isn't a far, far better movie than Into Darkness. This point is not up for debate.

And yet, the Khan riffs—when they work, which they sometimes don't–are the places where you catch a glimmer of the much better movie Darkness could have been, if only it had dared to follow through.

Kirk (William Shatner) and Spock (Leonard Nimoy) in Wrath of Khan

The climax of that story—the one about Kirk and Spock, and friendship, and facing and beating the no-win scenario—is played out in an almost pitch-perfect inversion of Spock's death scene in the original, and it works, because these characters are kids, and it's the splinter universe, and because Into Darkness has done a beautiful job of setting up Kirk's ultimate sacrifice as parallel to Spock's in Khan.

See, a lot of Star Trek Into Darkness is about Kirk slowly learning that he's not actually a very good captain yet. As Pike tells him early in the film, Kirk has gotten as far as he has on a mix of audacity, dumb luck, and Pike's confidence that his young protégé will someday hatch into a beautiful and command-ready butterfly. Kirk argues the point, but obviously something sinks in, and soon we see him learn not only to question himself, but to recognize the superior skills of his fellow officers.

Over the rest of the film, Kirk throws himself into danger more than once–not because he can't stand to stay away from the action, but because he recognizes that, of the crewmembers available, he is the most expendable. Spock is way, way better at commanding a starship. Everyone else on the core crew is otherwise irreplaceable. Kirk–well, by the time someone has to fix a damaged warp core leaking lethal levels of radiation, Kirk has come to terms with the fact that he's mostly just a guy with a knack for being in the right place at the right time. When he finally sacrifices his life to save the Enterprise, it's the climax of a long journey that, in retrospect, could only have had one possible destination: unexpected for the moment before you realize it was inevitable.

For a character as ego-driven as this version of Kirk, that is a *really *compelling arc, with an even more compelling climax.

The inversion of Spock and Kirk's deaths is the kind of twist that could easily have played as contrived without enough foundation, but here, it works beautifully. Much of Kirk's final conversation with Spock is almost verbatim from Spock's death scene in Khan, and here, for once, Into Darkness lives up to the comparison it invites.

Both versions of that scene are ultimately about Kirk and Spock's friendship. In The Wrath of Khan, it's about a friendship that's survived and grown over decades, characters whose understanding of each other goes way beyond speech. In Into Darkness, it's about lost potential: discovering that nascent friendship only when it's about to be lost forever. They're kids, and watching Kirk's terror and Spock's anguish as they face the captain's death together is utterly wrenching.

Even though I knew better, I let myself believe for a few short seconds that they might actually let Jim Kirk stay dead. That maybe, just maybe, Into Darkness had inherited some of that world-shaking audacity of its predecessors. That Abrams and co. would recognize that to toss Kirk right back through the revolving door would neuter the most powerful moment—the most powerful story arc—of the film.

Killing Kirk–really killing him, even just for time between this film and the inevitable sequel—would have been a brilliant move. It would have established the splinter-universe continuity as its own unique creature by means far firmer than even the destruction of Vulcan. It would have made it clear that the old status quo was a starting point—that here, now, everything was at stake. Sure, it wouldn't have fixed *Into Darkness *entirely. The pacing would still have been terrible. The plot would still have been riddled with holes. But it would have bumped it up from promising mess to flawed masterpiece.

But within ten minutes, Kirk's up and kicking. In fifteen, he's got the Enterprise, and every significant change and character development has fallen prey to the Teflon status quo, wiped away to make room for the next low-stakes adventure of the Starship: Now That We’ve Established the New Continuity Nothing Will Ever Really Change.

The strengths of the old Trek movies lay in their willingness to shake the world. The Wrath of Khan killed the fan-favorite main character. The Search for Spock brought him back, yes—but at the cost of the Enterprise. And then, after two movies of battles and explosions and grit and death, the core crew of the Enterprise flew off on their stolen Bird of Prey to find some humpback whales in 20th-century San Francisco, returning to what they hoped would be a court martial because the alternative was the end of all life on Earth. And it was only then that we got anything close to what we started with—the whole crew, together, on the bridge of the brand new Enterprise-A.

The old Trek movies weren't flawless, but they were brave. I'd trade the new films' pitch-perfect casting, epic battles, super cool uniforms and nostalgic call-backs for even a hint of that audacity–for the new Trek to do what Trek has always done best: seek out brave new worlds and boldly go where no one–not even Star Trek–had gone before.