The Marvel Cinematic Universe is one impressive accomplishment: a rapidly expanding collection of movies and TV shows which share a unified canon, all telling stories within the same fictional universe. While the actors portraying key roles are typically kept the same, behind the scenes, each movie features a variety of different writers, directors, designers and other filmmakers, all of whom are doing their best to maintain a cohesive overarching story.

Keeping track of various plot points, characters, props and other MacGuffins isn’t always an easy task, and while the MCU has a pretty solid continuity (especially compared with other franchises, such as the X-Men movie universe), directors can sometimes make mistakes, or don’t notice how a particular plot point may tie in with other movies in the franchise.

This has led to a few plot holes and weak explanations for character actions and abilities. Sometimes a movie will contradict established canon from a previous adventure, and sometimes lore that’s established in a movie is abandoned later on in the same film. While moviemakers do their best to give an explanation for oversights, those of us who don’t watch the director commentaries can end up getting confused. With that in mind, here are the 10 Worst Plot Holes In The Marvel Cinematic Universe.

*** Warning: This post contains spoilers about the various films in the MCU ***

10. Thor’s Age

The first Thormovie had a lot of exposition to dump on audiences before they could begin enjoying the movie. A lot of this is delivered by way of a story that Odin tells his two young sons, Loki and Thor. Audiences learn that, when the Frost Giants attacked Viking settlements on Earth, Odin and other Asgardians showed up to stop them. This battle led to the development of Norse mythology, as the humans who witnessed it thought the Asgardians were gods. While Thor was too young to participate in the battle, he expresses his wish to be a great warrior like his father one day.

When Thor is all grown up, he gets banished to Earth for trying to start up the war with the Frost Giants again. Erik Selvig recognizes Thor’s tall tales as being the stories that he grew up with as a child, and even finds a chapter on Thor (and a very accurate illustration) in a book of mythology in the local library. There’s just one problem: Thor has never visited Earth before, and was too young to fight in the battle with the Frost Giants a thousand years before. Somehow, the Vikings had exactly predicted Thor’s name, appearance and weapon of choice centuries before he’d start swinging around his mighty hammer.

9. Iron Man’s Power Source

At the beginning of the firstIron Man, Tony Stark gets shrapnel from an explosion lodged in his chest before being captured by terrorists. To keep the shrapnel from piercing his heart, his fellow prisoner, Dr Yinsen, installs an electromagnet in his chest which is powered by a car battery. To further prolong his life, Tony quickly replaces this with a makeshift ARC fusion reaction, providing far more power than the car battery could – enough, in fact, to also power the first Iron Man suit.

In spite of this impressive energy source (which Tony redirects his entire company to manufacturing), Tony’s Iron Man suits have a tendency to run out of power. The Mark 42 prototype in Iron Man 3, though, has an unusual power source: after having its battery drained by a cross-country flight, Tony resorts to recharging it with a standard car battery, rather than the improved ARC reactor in his chest which normally charges his suits. For some reason, Tony’s designs have gone full circle by Iron Man 3, and he’s back to relying on an inferior car battery.

8. Star-Lord’s Magic ‘80s Nostalgia Gear

Peter Quill’s Walkman is magic. That’s the only explanation for its ability to keep producing high quality audio for twenty years, without the tape wearing out or the batteries running dry. While it’s heavily implied that the leader of the Guardians of the Galaxy had never returned to Earth after his abduction at the hands of blue alien pirates, he must have found somewhere in the stars that sold AA batteries and a tape deck that he could install on his spaceship, the Milano.

In the climactic final battle on Xandar, the Milano is destroyed – Quill’s tape deck is seen in the wreckage, melted and burnt but somehow still functioning, albeit with an audible squeak. Thankfully, though, the technicians of the Nova Corp who rebuild Star-Lord’s ship have the tools to fully repair and reinstall 1980s Earth audio technology, and throughout all of this, the sound from Quill’s “Awesome Mix Tape Volume One” is still as flawless as ever.

7. The Broken Rainbow Bridge

The Bifrost, the magical rainbow bridge which allows Asgardians to travel to other realms, is made out to be a big deal in the first Thor movie. When, at the end of the movie, Thor destroys the bridge to save Earth, Loki warns angrily that Thor will never be able to see Jane Fonder, his love interest, again. The movie ends with Thor standing upon the broken bridge, wondering what Jane is doing and whether he’ll ever be able to return to Earth.

When, in The Avengers, Loki shows up with an evil plan, Thor is able to return to Earth without difficulty. There’s a throwaway line from Loki about ‘dark magics’ that Odin must have used to send Thor to Earth, but it’s never explained why this couldn’t be done sooner, and why Thor was so distraught at the end of his first film. In fact, by the timeThor: The Dark World occurs, the Bifrost has been completely fixed and there’s absolutely nothing stopping Thor from visiting Jane, apart from, apparently, his own sense of duty – instead he spends his evening pining for her. If getting back to Earth wasn’t really a big deal, why was Thor so upset at the end of the first movie?

6. Tony Perfects Regeneration Technology, Then Never Uses It Again

At the end of Iron Man 3, Tony Stark has to stabilize the risky Extremis technology in order to save the life of his partner, Pepper Potts – something that he does without effort, because he’s just that smart. In addition to giving the user the power to get really, really hot and breathe fire, Extremis is able to regenerate human limbs and tissue (although, as is seen on one of Aldrich Killian’s lackeys, Extremis will perfectly regrow an arm in minutes but won’t heal facial scars).

Having possession of an ultimate healing technology, Tony must have then decided to bury it in the Stark archives, for some reason. In Age of Ultron, Hawkeye is wounded and then treated with an experimental tissue regeneration technology which appears to be both slower and more painful than Extremis. In Agents of S.H.I.E.L.D., Director Phil Coulson has access to incredible medical technology, but for some reason can’t use Extremis to regrow his arm after it’s cut off. Perhaps Tony decided to slap a trademark on the new tech and keep it all for himself?

5. Howard Stark’s Genius Plan

Apparently, keeping scientific breakthroughs for personal use runs in the family. Tony Stark’s dad, Howard Stark, discovered a brand new element years before anybody would be able to fully synthesize it. Instead of sharing this discovery with the world, Stark Sr. decided to keep it a secret, and left it as a series of clues in a map of his off-brand Epcot Center for his son to one day discover.

Howard Stark’s plan required Tony to jump through a few hoops. In Iron Man 2, Tony would need to get access to a collection of resources that were being kept in S.H.I.E.L.D. archives, would need to watch his father’s blooper reel from an old movie to get the hint as to where he might find this element, then stare way too long at a model map. Having discovered the particle makeup of this new element, Tony realizes that technology is still not advanced enough to create it, but he goes ahead and synthesizes it anyway, contradicting his own dialogue, because he’s Iron Man and can do whatever he likes.

All of this is very convenient, because the element Howard Stark discovered is the perfect ingredient to save Tony’s life from palladium poisoning. It probably would have been easier if Howard Stark had just shared his discovery with the world though, and saved Tony the map-based homework.

4. The Infinity Gauntlet in Odin’s Vault

In the first Thor movie, Odin locks up all of his rarest and most dangerous treasures in a secure vault. Loki enters the vault several times to get a close look at the Frost Giants’ power source, which is kept under careful watch by the Destroyer.

As a cute Easter Egg, one treasure which can be seen in the vault is the Infinity Gauntlet, a nod to a popular Marvel comic storyline. It’s clear that at the time the movie was written, Marvel didn’t have the full arc for the MCU planned out yet, as the Infinity Stones and Gauntlet are to play a major role in the upcoming Infinity Wars movie duology. At the end of Age of Ultron, big baddie Thanos is seen putting on the gauntlet. Marvel honcho Kevin Feige has explained that there are actually two Infinity Gauntlets, which feels like a bit of an ad-hoc explanation.

It’s probably not fair to be too harsh on Marvel for not having planned every element of their movies a decade in advance, but while MCU producer Kevin Feige has attempted to explain away the plot hole off-camera by inventing lore on the fly, this might be an example of a plot hole that’s better to ignore than to retcon.

3. Thor Takes the Tesseract to Asgard, Leaves Behind Loki’s Scepter

In The Avengers, Thor makes a big point of taking the portal-generating, energy-spewing Tesseract back to Asgard with him when he apprehends and arrests Loki. When, in the follow-up movie, Loki’s staff falls into the hands of HYDRA, the Avengers assemble to retrieve it, and Thor makes a big fuss about taking it back to Asgard, only giving Tony Stark a little while to play with it and accidentally create Ultron.

So if Thor is adamant that the scepter return to Asgard, why didn’t he bring it with him when he took back the Tesseract? The weapon is in the Avengers’ possession at the end of the battle, but at some point they put it down somewhere and forget about it until the start of Age of Ultron.

2. Tony Stark Ignores his Suit Collection Until The Last Possible Second

Iron Man 3 sees Tony Stark stuck without a functioning Iron Man suit for most of the movie, having to wait for his prototype Mark 42 to recharge before it can be used in action. At the end of the movie, in a climactic display of CGI lights and metal, Tony initiates the “House Party” protocol to bring well over thirty other suits to his rescue in order to save the day and defeat the bad guys.

So if all it took to call another suit was to give J.A.R.V.I.S. the secret passcode, why didn’t Tony do so sooner? It would have been a lot quicker and easier than waiting for the broken Mark 42 to charge, and having a suit would have made life a lot easier in the many death-defying gun battles Tony has before finally calling for a House Party.

1. The Avengers Only Assemble When They Feel Like It

Probably the biggest gripe that movie fans have with the MCU is that The Avengers basically made every subsequent solo movie feel less exciting. After seeing a whole host of costumed heroes work together to stop an alien menace, it’s difficult to understand why they don’t work together regularly on other problems, such as S.H.I.E.L.D.’s attempts to murder everybody who complains about the government on Facebook. Considering that Tony Stark is a target during the climax of Captain America: The Winter Soldier, it’s odd that Cap doesn’t decide to include him. Ditto to when Tony is stranded alone without backup in Iron Man 3: making a call to Cap or his good buddy Bruce Banner seems like it might have helped things go smoother.

Of course, there’s a very simple explanation to why the Avengers don’t assemble every time a single hero faces a threat: if every movie turns into an Avengers sequel, there’s no point in even having solo movies anymore. Still, considering the extensive cast of Captain America: Civil War and the fact that Thor: Ragnarok is also going to star the Hulk, perhaps Marvel have decided that on this point, their fans were absolutely right.

Conclusion

Over the course of multiple movies, plot holes are going to inevitably sneak in. Considering the size of the MCU, it’s impressive that there aren’t more problems with the canon, and the filmmakers behind the movies are always eager to try and close a story gap if they’ve got a chance.

No story is perfect, though, and it’s important to hold the MCU to a high level of accountability for what errors do slip in, to ensure that Marvel keep delivering high quality, enjoyable movies for years to come.

Have you spotted a plot hole that isn’t on this list? Do you think one of these points is being too harsh? Have your say in the comments below.

Captain America: Civil War will release on May 6, 2016, followed by Doctor Strange – November 4, 2016; Guardians of the Galaxy 2 – May 5, 2017; Spider-Man – July 28, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; The Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel – March 8, 2019; The Avengers: Infinity War Part 2 – May 3, 2019; Inhumans – July 12, 2019; and as-yet untitled Marvel movies on May 1, July 10 and November 6, 2020.