[Spoilers related to Age of Ultron and the Marvel MCU films in general will be present in the following Post. You've been warned.]
[Oh, and this will likely be quite long. You've been warned. ;P]
Since the release of Age of Ultron, I've seen quite a few articles or comments pop-up regarding various aspects of Thanos/Loki/Loki's Sceptre/Infinity Stones that seems to call out aspects of the Marvel Cinematic Universe films/material as "Plot Holes" when, in fact, they can be easily explained with a bit of research and common sense (along with a few easy leaps of the imagination due to certain things that haven't been officially talked about or revealed yet). I'm going to attempt to clarify a few of these and clear up any misconceptions.
Question #1) Why didn't Thor take Loki's Staff back to Asgard at the end of Avengers 1 (especially if Thor wanted it so badly at the beginning of AoU)?
We'll start this out with one of the larger "plot holes" that people have been shouting about. At the end of the original Avengers, Black Widow uses the Scepter to shut down the Tesseract's wormhole. Natasha is then seen holding it mere inches away from Thor while the whole group stares down Loki, forcing him to give up. Thor then takes Loki and the Tesseract back to Asgard, but leaves the Scepter on Earth (assumed to be in the hands of SHIELD). Suddenly, at the beginning of Age of Ultron, Thor cares deeply about reclaiming the Scepter (in fact, that's the only reason he's there at the beginning of the film).
Now, let me clear one thing up: Thor had no idea that Loki's Scepter housed an Infinity Stone until he realized it during Age of Ultron. We saw the scene where he realizes it. This doesn't make Thor dumb (at least no more than the other characters who refused to "look within" to paraphrase Ultron), as he had no reason to expect it to house an Infinity Stone. Thor had SOME previous knowledge of the Infinity Stones in general (Tesseract/Aether), but Loki's Scepter flew under his radar.
With that settled, let's look at WHY Thor took Loki and the Tesseract back to Asgard. Now, it's pretty obvious why he took Loki back to Asgard and to an Asgardian Prison Cell: He came from and belongs there (well, kinda :P). And, oddly enough, that's the exact same reason that the Tesseract goes back to Asgard with Thor at the end of Avengers: it came from/belongs there.
If you re-watch Captain America: The First Avenger, they find the Tesseract behind a sculptured mural of Yggdrasil (The World Tree) and Red Skull says "The Tesseract was the Jewel of Odin's Treasure Room". Now, we don't exactly know WHY or HOW the Tesseract originally got from Asgard to Earth, nor is that really an important plot-point at the moment (though it may be filled-in for us in a future film or MCU product. My personal theory is that Odin placed it on Earth for the same reason that Volstagg placed The Aether with The Collector). The important thing is that it came from Asgard and was placed on Earth, so of course it would go back to Asgard if it came to light and started causing chaos on Earth.
The Scepter, however, did NOT come from Asgard and nobody (save for Loki, Thanos, and maybe The Other) knew where the Staff came from or what power it possessed (I highly doubt that even Loki knew the true power of the scepter and what it contained, as that's probably something that Thanos would keep to himself). Asgard, in that instance, had no claim over the scepter, especially if SHIELD wanted it for experimentation.
Some people think that it's Thors job to remove any dangerous "alien" influences and devices from Earth (as that's kinda been his plot over the MCU), but that's not his job and there are plenty of other "alien" devices still on Earth in the MCU to prove this point. It's unrealistic to just automatically assume that, since the Staff was being used by Loki that Asgard would have first claim to it (or even want it) or that Thor had some obligation to bring it back to Asgard at the end of The Avengers (He didn't).
Fast forward a few years, however, after Thor has had a run-in with a second Infinity Stone (The Aether) and SHIELD has collapsed to reveal its Hydra ranks within. Suddenly, Thor realizes that all of those devices (and the scepter itself) were no longer under the protection of SHIELD and likely being experimented on and misused. He still doesn't know that it's an Infinity Stone, but he now has an obligation to retrieve the scepter from the "bad guys" and place it into more capable hands (his father, we assume). Who gave Thor the official order to retrieve the scepter? Loki did, as he's currently ruling Asgard in place of Odin (unbeknownst to everyone else). Of course Loki would want such a magical staff back (perhaps he even suspects that there's more to it now than he thought before).
Now, of course what happens doesn't play out exactly like that due to Thor having some pesky visions and insight, realizing what is within the scepter (and, possibly, that Odin is actually Loki depending on what we find within the cut/extended scenes). Thor suddenly doesn't want the scepter to go back to Asgard and assists in the creation of Vision to protect the gem. In the context of all of this, Thor's inaction with the scepter before and his desire for action (and a change of plan) now suddenly make a lot more sense.
Question #2) Why did Thanos give his only (assumed) Infinity Stone, The Mind Gem, to Loki? Isn't that a large gamble?
Now that we've settled Thors motivations/actions/realizations and what that means, let's go back in time a bit to the original Avengers again. In it, Thanos (we assumed and now pretty much know) gave Loki the Scepter with the Mind Stone housed within it. At that point, we also weren't aware of any other gems he might have in his possession, so let's assume (using some details of future films as well) that the Mind Gem was the only Infinity Stone that Thanos had possession of at the time. Why would Thanos give his only gem away to someone like Loki in HOPES that he would collect only one more gem (The Tesseract) and return them to Thanos willingly? Well, that's where things get interesting.
Now, assuming that Thanos isn't just written dumb and making poor decisions (he is eternal and known to be quite intelligent and powerful, after all), then he obviously had some sort of scheme that he was placing in motion by giving Loki the scepter, and not only is that true, but (as we find out in AoU) it is double-true (more on that in a bit).
So Loki was armed with the Staff and told that it can make thralls and that the staff could be used in conjunction with the tesseract to open a portal in space, allowing a waiting Chitauri army to come to Earth and cause havoc. Loki, however, is a smart enough fella to realize that he was simply a pawn and that, if the plan was successful to a T, that he himself wouldn't be the one in charge for long. But for Loki, that's not such a big deal as he only cares about Earth and its destruction so much because it hurts his dearest brother Thor (which was probably the icing on the cake to get Loki to go along with Thanos' plan).
Loki knew that "his" plan in the original Avengers was flawed and that it likely wouldn't work out as planned, but that was of no consequence to him, as he'd get to go home to Asgard one way or another, which was his true personal goal (Stark, at one point in Avengers, even comments on this and gets rather close to the point by telling him that there's no throne for him here; no possible way he and his plan would have came out on top). So Loki is taken back to Asgard with the Tesseract but the Scepter is left on Earth (explained above).
The true question, the one we don't have an answer to yet, is: Was THAT part of the plan all along, to get Loki and the Tesseract back to Asgard (where one of the two Infinity Gauntlets is also possibly held?. At this point, it could go either way.
Personally, I don't think that Loki knew that the scepter housed an Infinity Stone (he would have taken a different approach to its security), or that Thanos was even involved with the plan, as Loki is seen discussing with The Other (another pawn of Thanos) rather than Thanos himself. Loki wants many things, but I don't think destruction for destruction's sake (which is what Thanos is after) is something that he would agree to go along with.
I think that it was Loki's plan to get taken back to Asgard, but that the scepter and tesseract were of no importance to him after that (at least until he began to put the pieces together himself and, possibly, realize the threat of Thanos). Loki (in guise of Odin) sent the Aether to The Collector at the end of Thor 2 and sent Thor to Earth to reclaim the scepter at the beginning of AoU. Either that's a big coincidence, or Loki himself wants to claim the Infinity Stones now that he's aware of them. This could either be due to an alliance with Thanos or in an attempt to thwart Thanos. At this point, we just don't have enough information to tell which is which (Thor 3 will probably enlighten us, though).
By this point, it seems like Thanos is/was content with letting others play his game for him (and that trope, so far, has continued whenever an Infinity Stone has popped up in the films such as with Thor 2, Guardians of the Galaxy, and Age of Ultron). However, I DO believe that Thanos intended the scepter to be sent to Earth and that he had a back-up plan for it in case the Chitauri Invasion failed (Ultron).
Now, it's possible that Thanos has the Time gem or Soul gem still, but it's unlikely as we see him putting on his Gauntlet at the end of AoU and it has no Gems in it. He also says something that confused a lot of people in the theater and seemed to come out of nowhere based on the rest of the film: "Fine, I'll do it myself".
What does this mean? Did he have another plan in motion that failed during the film? Yes, yes he did.
At the beginning of Age of Ultron, within Strucker's base, we see the scepter (along with a lot of robotics from what will eventually be Ultron and a lot of Chitauri debris). Now, you might say "wait, but Ultron wasn't created in the film till much later" and that's true, in a sense. The actual name, ideology, and motives of Ultron were created later, but as stated in the film itself the Gem of the scepter (The Mind Stone) had what can only be described as an Artificial Intelligence within it.
I'm positive that certain cut/extended scenes on the AoU Bluray will shed a bit more light on this (just as it will shed more light on Thor and his visions/realization about the stones and scepter), but until then we can only make a couple broad, educated assumptions about this AI and what Hydra were up to with it. We know that Strucker had the staff from AT LEAST the end of Winter Soldier (though, it's hinted that he's had it longer than that even, as The Twins were already created by that point). He and his team (including Dr. List) had been experimenting on the Staff for quite a while up till that point, so we can assume that they noticed the AI element (Stark/Jarvis noticed it pretty much instantaneously). We can also assume that the "Ultron Bodies" in the Sekovia base were created in response to this, as an attempt to move/copy this AI of the scepter into the bodies.
Unfortunately (or fortunately?) Stark takes the Scepter back to Avengers Tower and he and Banner do a bit of Science-Bro's-ing on it (along with quickly mentioning their dream peacekeeping project: Ultron). The AI of the stone then destroys Jarvis, browses what appears to be the entire internet and all info about Ultron/The Avengers, and then uploads this consciousness to the Iron Legion Drones. Because of the mannerisms/dialogue of Ultron throughout the film, we can easily assume that Starks personality (or at least part of it) was implemented into Ultron somehow (though the movie never explicitly says this). Again, this will probably be housed in the extended/deleted scenes of the film. This caused Ultron to go "mad" and essentially backfire, wanting to wipe away all of humanity in order to "save it". So, yeah, he went Stark-raving Mad.
Or did he?
Afterall, the scepter (or at least the gem) was originally given away by Thanos, given to Loki, and sent to Earth. It's not stated, but it's assumed that this "AI" had been in the gem since its first appearance in The Avengers. And who placed this AI inside the gem? We can't know for sure, but judging by how Thanos says "Fine, I'll do it myself" and other minor details throughout the films, we can easily take an educated guess and say that Thanos KNEW the AI was in the scepter (possibly even placed it in there, like a virus) and that that was one of his "backup" plans, or even the main plan.
Ultron (well, not the name, but everything else) was Thanos' Ace in the hole: a virus within the gem (not the gem itself) that would eventually become a mechanical army and bring about a worldwide destruction on Earth so that he could simply walk in and take back his gem (along with any others that he'd been ever-so-slightly influencing and manipulating).
Unfortunately for him, all of his plans "failed" so far (mostly due to the unknown variable/heroes of Earth and the galaxy). But fortunately for him, I don't think we've even seen all of his schemes that are at play yet. The AoU deleted/extended scenes and Thor 3 will likely shed a lot more light on these subjects/questions, however. #marvel #mcu #marvelcinematicuniverse #thanos #loki #thor #avengers #ageofultron