First and foremost, "Captain America: The Winter Soldier" is the best action film out of the entire Marvel movie universe so far, bar none. Just in terms of sheer impact and choreography and execution and clarity of geography and did I mention impact because DAMN. If that is all that this film did well, that would be enough for me to recommend it.

Beyond that, though, "Captain America: The Winter Soldier" is a tremendous piece of pop entertainment, smart and engaging and featuring a home run movie star lead performance by Chris Evans and the best overall supporting cast in one of the Marvel movies in terms of everybody having something significant to do and everyone being written for to a degree where they're playing people and not just types. Written by Christopher Markus & Stephen McFeely, this movie hits the ground running, literally, in a great scene where Steve Rogers (Evans) meets Sam Wilson (Anthony Mackie), a former member of a para-rescue unit who now works at the VA hospital. In one quick moment, they dispense with any need for fish out of water jokes and they introduce the notion that Steve is struggling with the bigger issues that affect him as a man out of time. He is having his doubts about the work he does for S.H.I.E.L.D., and in the film's first big set-piece, we see just how wet that work actually is.

They made a smart choice to have Natasha Romanoff aka Black Widow aka Scarlett Johansson paired up with Cap for most of the movie. She's got a different perspective on the kind of work they do, and a very different backstory, and contrasting the heroism of these two as well as the methods creates an interesting tension, especially once things really start getting crazy. In that first big set-piece, there are two totally different threads being followed. First, there's the actual mission, in which they're supposed to liberate a S.H.I.E.L.D. boat that has been seized by pirates led by Georges Batroc (Georges St-Pierre) and rescue the hostages aboard, particularly Jasper Sitwell (Maximiliano Hernandez). Watching Cap move through the boat, taking out pretty much the entire crew single-handedly, it's obvious right away that directors Joe and Anthony Russo have a knack for comic book action in particular, but the close-up bone-breaking kind. Captain America is a wrecking crew in this film. He isn't shy about using a throwing knife or pretty much shattering a sternum with a strike of his shield. He doesn't pull his punches. He's got a mission, and when it comes down to it, the strike team that was sent with him, including Brock Lumlow (Frank Grillo) and Jack Rollins (Callan Mulvey), pull the triggers and put the pirates down.

The other thread is a playful but genuine banter in which Natasha is trying to figure out who she can set Steve up with, because she's convinced that he needs that connection. They play it for the laughs, but there's something real underneath it, and it's interesting that Natasha simply isn't an option herself. It seems like the easy lazy choice would be to play their relationship as a possible romantic or sexual entanglement, but they don't even hint at that. After all, Steve's feelings about Peggy Carter (Haley Atwell) are still fresh for him, and if there's anything that haunts him, it is the loss of an entire life with her. Evans and Johansson have great chemistry, and any scene that is just the two of them talking is a winner.

There's not much time for that, though. When they get back to DC, it's apparent that Natasha was sent to retrieve more than the hostages, and whatever she took from the boat sets off a chain of events that manages to snare Nick Fury (Samuel L. Jackson playing the biggest role he's had in any Marvel film so far), Maria Hill (Cobie Smulders), and as Alexander Pierce, the guy above Fury in the chain of command, no less than Robert freakin' Redford, who brings his A-game. This is not a case of someone dropping by to pick up a paycheck. Pierce is a real character, and Redford's really good playing him.

If you want to go in relatively spoiler-free, stop here. Suffice it to say the scale of the film is impressive, the action is relentless, and the plot manages to genuinely shake the power structure of the entire Marvel movie universe. This is not a film designed to maintain the status quo. It is a film full of big choices that will have a big impact on every other film that's still in the works. The Russos turn out to be an inspired choice, and the end result is a film that ranks very near the top of the list out of any of the films made by Marvel Studios so far.

Without giving the whole game away, it's safe to describe this as a story in which no one is who they seem, and the entire history of the Marvel movie universe so far is thrown into question. This is very much a direct sequel to the first "Captain America" film, and it feels like this movie pays off legwork that's been done in a number of the films so far. We see characters like Senator Stern (Garry Shandling) again, and we're forced to re-examine who they are and what their motives may have been in earlier films. I'm fascinated by the idea that "Marvel's Agents of S.H.I.E.L.D." is going to have to address the events of this movie, because there's no way they can simply keep things rolling along on the show the way they have been so far. No way. It's not possible. So many big cards are flipped over by this film that it's going to send major ripples through that show, and it may end up completely subverting the meaning of that title.

I really like what they give Nick Fury to play in this film, and I feel like Jackson knows they're giving him some real meat this time. He is great in the film, and watching Fury have to deal with no longer being the man pulling all the strings is interesting. It makes him feel like a character finally instead of an exposition delivery device. Emily VanCamp joins the franchise as Sharon Carter, who has a complicated history with Captain America in the comics, and who is established here as someone of substance, someone worth bringing back in future films. The same is true of Sam Wilson, and when he is finally revealed as The Falcon, it's very cool and very grounded. It doesn't feel like a sudden left turn into a different film. It also gives the Russos an opportunity to stage some action scenes that take place on three or four different planes at once, and it's dynamic and aggressive and very effective.

And what about The Winter Soldier? Well, they make sure in this film to underline just how important Bucky Barnes was to Steve Rogers, and there are a few nice moments that fill in more details from the pre-Captain America days, including a solid scene with skinny nerdy Steve Rogers again. When the Winter Soldier shows up, he is a figure of genuine menace, and he is incredibly powerful. He and Captain America are a genuine match, and in many ways, it feels like the Winter Soldier is better at what he does. It makes it interesting and tense every time they have to clash in the film. He's not scared of Captain America at all, and he's not the sort of guy who does subtle. When he goes into kill mode, he's a force of nature, and it's really harrowing.

There are two post-credits scenes here. The first was directed by Joss Whedon, and it's basically a direct bridge to the opening sequence of "Avengers: Age Of Ultron," introducing Baron Von Strucker (Thomas Kretschman) and two other new characters, and they both look awesome. Then there's a scene at the very end of the entire film that simply puts a nice button on this film's story. Make sure you stay for both, though.

The only real hesitation I have about this is the same problem that I had during "Iron Man 3." Once you've established that Thor and Captain America and Iron Man and the Hulk all exist in the same world (and this movie goes out of its way to introduce the name "Stephen Strange" for the very first time), then you can't help but wonder why Captain America can't reach out to Tony Stark for help with something. There's a moment in the film where Steve and Natasha turn to Sam Wilson for help and they explain, "Everyone we know is trying to kill us." Well, that's not true. Tony Stark's not trying to kill you, and he seems like he'd be a great resource. If I read Kevin Feige's comments last year when "Iron Man 3" came out correctly, this film is meant to be taking place at the same time as that film, and so we're meant to see that each of them is too busy to help the other, but since neither film explicitly states this, it just comes across as this nagging frustration. I understand that you want to save the team-ups for the "Avengers" films, but it would be nice to at least acknowledge that there's a reason you can't bring them all together to solve this problem.

I think there are some genuine questions about our own current surveillance state raised by the film, but it doesn't feel like someone shoe-horned in a political metaphor as it did with "Star Trek Into Darkness," where Robert Orci's obsession with "false flags" turned into a plot that simply doesn't make sense when you start to take it apart. This film is tightly plotted, and when the final threat is revealed, it's a genuinely ugly, scary idea. If this is how Marvel plans to handle Captain America films moving forward, I hope we get 50 more of them.

Once again, make mine Marvel. "Captain America: The Winter Soldier" is a huge success for them on a story level, and a fascinating provocation to anyone making Marvel movies set after this one.

"Captain America: The Winter Soldier" opens in theaters everywhere April 4, 2014.