Which one is harder, issue number one or issue number two of a comic book?

In a first issue, you have to explain a premise. You have to set up a world. You have to convince people to come back for a second issue. There's a lot of things that have to work, or there's no reason for anyone to keep reading. WIth a second issue, it seems like some of that pressure would be off, but I feel like it might be the opposite. In many cases, it feels like the pressure of finding the right second story to tell is difficult because every option is open and there is no template for what a second issue has to be.

Marvel struggled with "Iron Man 2," easily the weakest of the Phase One films they released. I think there are plenty of things to enjoy in "Iron Man 2," but I also think it's a structural mess, and in many ways, it feels like little more than a bridge between other films. This time around, the script by Christopher Yost and Christopher Markus & Stephen McFeely aims to tell an epic story that introduces more of the Nine Realms than just Midgard (aka Earth) and Asgard, and there are many things that the film gets right. In particular, I like the way they mash up the science-fiction and fantasy elements in a way that would probably make Jack Kirby tap-dance if he'd lived to see it.

Picking up as Thor is finally finishing the massive clean-up required after Loki attempted his coup to grab control of Asgard, "Thor: The Dark World" looks backwards for its set-up to the days where Bor (Tony Curran) was fighting a war against the Dark Elves led by Malekith (Christopher Eccleston). He managed to lead the forces of Asgard to victory, and they took the weapon that was developed by Malekith, the Aether, and hid it somewhere. Odin was raised to believe that all of the Dark Elves were killed, but very quickly in this film, it becomes clear that simply isn't true.

The Aether is really only valuable during The Convergence, which is an event where all Nine Realms line up perfectly. And since that's about to happen again, it's time for Malekith to show back up, claim the Aether, and destroy the universe. And while that all sounds suitably dramatic, it's sort of not. Malekith is a non-entity as a character. He walks around, says a few vaguely threatening films, and basically watches special effects happen around him.. His second-in-command, Algrim (Adewale Akinnuoye-Agbaje), may be transformed into the creepy-looking Kurse at one point in the film, but he is equally bland as a character. There's nothing to him. He delivers maybe three lines of dialogue before he's turned into a giant monster, which seems like a waste of a really fun actor.

There's a whole lot of threads from both "Thor" and "The Avengers" to service, and that makes "Thor: The Dark World" feel very busy in places. The relationship between Jane Foster (Natalie Portman) and Thor (Christopher Hemsworth) was left up in the air after the first film, and there's a lot of attention paid here to the way characters feel about that relationship without really grappling with the relationship itself. It's clear that Odin does not want Thor to be with a mortal, and Loki openly mocks Thor for caring about a human who will be gone in less than 100 years, what Loki calls "a heartbeat." Even Lady Sif (Jaimie Alexander), who looks enough like Natalie Portman to suggest that Thor has a very, very, very specific type, is obviously upset to see him pining away over someone else.

In addition, the script struggles mightily to give Erik Selvig (Stellan Skarsgard) and Darcy (Kat Dennings) enough to do. Dennings scores huge laughs several times in the film, and I haven problem with her presence here. She is very enjoyable and seems to be having fun. I'm just not sure it makes organic sense to shoe-horn her back into this particular story. Perhaps the film's biggest issue is something that seems like a Catch-22 for Marvel, in that they spend a lot of time with Loki in this film, even though he's not the star of the film. Marvel knows full well that Loki is a fan favorite, and it feels like they lean on that pretty hard. He's got some great scenes, and Hiddleston is once again terrific playing the part, but there are definitely places where it feels like the filmmakers are more interested in him than they are in Thor.

In addition, the structure of the film is odd. Right around the time it feels like things are about to kick into high gear, the movie ends. So much time is spent moving chess pieces into place that when they do finally finish setting everything up, the movie's done. I feel like the Warriors Three are sidelined more aggressively here than they were in the first movie, and watching someone waste Ray Stevenson or Alexander or even new cast member Zachary Levi as Fandral, when they're all obviously so eager to play, is a mistake.

There are strong action sequences, I love the way they've expanded the world and redesigned Asgard, and I still think the cast is pretty much perfectly suited for the roles they're playing. Rene Russo gets one really nice moment here, and I think Portman's chemistry with Hemsworth is very charming throughout. Of all of the Marvel heroes that the studio has in the movie rotation right now, Thor is the only one where the love interest actually seems to generate some real heat between the leads. I thought Haley Atwell was great in "Captain America," but there's something disarmingly carnal about the looks that Jane Foster gives Thor after he flies her through the Bifrost or beats the hell out of a crazy monster in front her.

You can see some of the scars left by post-production tinkering with the picture, including some last-minute reshoots, but for many audiences, the slicker overall look of the film will smooth out many of the film's rougher moments. Make sure you stay for not one but two post-movie scenes, one during the credits and one after, and it's safe to say that the last ten minutes of this film sets "Thor 3" into motion, lays out part of the game for the rest of Phase Two and possibly even "The Avengers 3," and gives us our first look at one of the next big Marvel gambles. That's a lot to pack into a very short time, and it seems symptomatic of the film as a whole. Is it possible to be both overstuffed and too slight? If so, that's "Thor: The Dark World" in a nutshell.

"Thor: The Dark World" opens everywhere on November 8, 2013.