The thing is, whether Loki is the villain you love or the villain you love to hate (or just hate), there are two things about him that nearly everyone seems to agree on. One, Tom Hiddleston makes an awesomely compelling supervillain; and two, Loki’s apparent masterplan in The Avengers makes no damn sense.
While Loki is definitely not rowing with all oars in the water, he still is enough on the ball to face off against all the Avengers and hold his own against most of them, and spout dramatic speeches while doing so. He comes across as scheming and manipulative, but his manipulations are baffling. According to his various monologues, his self-stated goal is to rule Earth, to save humanity from itself under his evil benevolent reign as supreme high king and make goat-horns an obligatory fashion statement.
To do this he calls down an alien army on New York City (notably not the capital of anything) and proceeds to wreck the place, while making no demands of any sort, no “Surrender this planet to me or else”; and not sending his army beyond the city limits. He also makes a big production of riling up the Avengers, ostensibly so he can utterly crush them in the final showdown; only most of his last act face-offs with them are out of the public eye. None of this seems like a feasible way to achieve world domination.
There’s also the whole thing that back at the end of the Thor movie, Loki specifically tells Thor, “I never wanted to rule, I only wanted to be your equal,” and he had not the slightest interest in Midgard. So his new obsession with ruling Earth is either to piss off Thor (maybe by showing he’s a better king?) or…something else entirely is going on.
The two primary theories I’ve seen explaining what the heck Loki is doing are that he was to some degree under the Chitauri’s mind control same as Hawkeye and Selvig; or that the whole Earth invasion was really a Xanatos gambit for Loki to get taken back to Asgard so he could go treasure-hunting. There’s quite a lot of evidence for the former theory, while the latter is especially appealing because it’s in keeping with comics!Loki’s master manipulator skills. But one of the things that makes Loki a fun supervillain is that at any given time he always has half a dozen different motivations, and while he might’ve been a bit brainwashed, and getting back to Asgard was probably his goal at the end, we think he was working on a different project for most of the movie.
Namely, the annihilation of the Chitauri army.
At the end of Thor, Loki falls off the Bifrost, but not to his death - somehow he ends up on Earth (or at least is magically projecting himself to Earth) where he induces Erik Selvig to get involved with SHIELD’s work on the Tesseract. However, Loki is not the only one after the cube; it’s also an interest of Thanos, the big bad revealed at the end of The Avengers, and the power behind the Chitauri. Somehow between Thor andThe Avengers, maybe because of that mutual interest, Loki falls in with Thanos and the Chitauri. And given how strung-out he looks at the beginning of the movie, it wasn’t a fun time.
Loki’s partnership with the Chitauri seems fraught. While he supposedly commands their army, when he talks to their upper management they insult and threaten him - “You think you know pain? He will make you long for something sweet as pain” and end their chat with a psychic bitchslap that probably would’ve broken a mortal’s neck.
From that interaction, it’s not too far a stretch to suppose that the Chitauri have a hold on Loki - it could be a mental influence; it could as easily be the threat of death. If they can smack him around long-distance, it’s possible they could actually kill him at any time. Considering they can contact him, they can probably watch him as well (in the final invasion Loki summons the second wave just by murmuring for it, no radio in sight). They know Loki is a tricky bastard; they’re keeping him on a tight leash.
A leash Loki wants out of. “Freedom is life’s great lie,” he says, but that’s his greatest lie; as a trickster, freedom is what Loki values above all else. He’s mouthing the Chitauri/the Tesseract’s platitudes to convince them he’s drunk the kool-aid and is on their side. Meanwhile Loki is doing everything he can to set up the Chitauri’s ultimate demise, both to be free of them and as payback. His plan is pretty straightforward: get together a force strong enough to fight the Chitauri, and then summon his alien army and watch them get wiped out.
Loki wanted the Avengers to assemble. In particular, Loki wanted the Hulk - how he found out about Bruce Banner’s condition is unclear, but he obviously believes the Hulk is powerful enough to take on his enemies. To that end, after stealing the Tesseract and starting on constructing the portal, he arranges to get himself captured and taken to SHIELD, all for the purpose of activating the Hulk. This is confirmed as Loki’s purpose, except why he wants the Hulk awakened isn’t clear - if he just wanted the Hulk to take out SHIELD, why doesn’t he do more himself to take them down?
Loki’s under a serious limitation; he can’t openly explain his plan or his problem to the heroes, because if the Chitauri get so much as a hint that he’s working at cross-purposes, they can instantly gank him. So he’s got to play the part of the megalomaniacal villain, crazy enough that the Chitauri don’t question his more questionable actions. Such as letting his most dangerous supposed enemies live.
Loki repeatedly has the chance to kill various Avengers, but fails to do so, even though he has no problems killing non-superheroes. Despite what Fury says, Loki doesn’t really seem to enjoy killing so much as just not care about it one way or another; regular humans are only a means to his end. He brutally kills(???) Coulson in front of Thor for the same reason that Fury later uses Coulson’s death for - as motivation to get the Avengers to come after him, and more importantly, come after his army. On the other hand, when he confronts Tony Stark at the end (“And you’ve pissed off all of them.” “That was the plan.”), Loki first tries to scepter-possess him; when that doesn’t work, he grabs Tony and throws him out the window - rather than just stabbing him, or snapping his neck, or any of a dozen other ways he easily could’ve taken him out. Throwing Tony out the window was a test: either he’d somehow survive the fall (and therefore would prove himself strong enough to be useful in the coming fight) or else he’d be useless and die, in which case the other Avengers would be that much more pissed off and eager to take care of Loki’s Chitauri problem.
(It’s possible that Loki is cranky with Tony for another reason. He picked Stark Tower as his base of operations for several reasons, not least of which being it was the most obvious place in the world to get the Avengers to come find him, even if he couldn’t tell them outright where he was located. But also, as Stark’s “castle”, Loki might have been assuming it to be one of the better-defended places on the planet, somewhere most able to fend off an alien invasion. He might even have assumed that Tony would have some safeguards to protect the local population (or maybe not; they are just mortals). (Either way, the question of why the hell Tony (and SHIELD) didn’t call for Manhattan to be evacuated as soon as they figured out it was Chitauri Ground Zero is going to irritate me until the end of time…))
Loki also might be trying to indirectly explain himself to Thor. On their conversation on the cliff-top, Loki keeps saying things that Thor knowsaren’t true (such as that Thor threw him off the Bifrost, rather than Loki choosing to let go; and repeating his claims about wanting to rule even though in their last conversation Loki outright told Thor he didn’t want that). Maybe he’s trying to get Thor to figure out for himself that something is wrong, and his rising temper is impatience that Thor is not getting it (not until right at the end, when Iron Man so rudely interrupts.) At their confrontation on Stark Tower, Loki is close enough to kill or at least seriously injure Thor, but instead gives him a little stab in the side with a tiny knife that does no apparent damage - he doesn’t want Thor out of the battle. In fact, dropping Thor out of the SHIELD airship, though he claims is an attempt to kill Thor, was likely the opposite - the airship was going down, and Loki didn’t want one of his key fighters to be blown up or stuck on the bottom of the ocean.
Then there’s the scepter. It’s definitely a major power boost, but it’s the Chitauri’s, not Loki’s. Is the scepter in fact Loki’s leash? We know it can influence moods as well as mind-control; it might be exerting pressure on Loki, if not to the extent it does on mortals. And the Chitauri might’ve warned him not to try to toss it. In which case that’s another advantage to getting himself caught by SHIELD - it gives him a perfectly logical reason to be separated from the scepter as much as possible.
Meanwhile Erik Selvig, even under mind control, manages to build a backdoor into his Tesseract-powered portal-opener. Or was that really his idea? Loki had mental influence over Selvig at the end of Thor. Perhaps he maintained that influence, even when Selvig was being controlled by the Chitauri’s scepter. Selvig’s backdoor would be very useful for Loki - it uses the scepter to close the portal, and apparently destroys its power in the doing (in the end, Natasha has the scepter, but its light has gone out.) Loki’s plan all along might have been that once the Chitauri were taken out, he would close the portal with the scepter, destroying Thanos’s hold on him, and then grab the Tesseract for himself and abscond.
Which might have gone great, if Loki hadn’t slightly miscalculated just how hard the Hulk can smash.
Still, the majority of his plan is a complete success - the Chitauri are defeated, the scepter is destroyed, and Loki himself is alive and intact and - along with the Tesseract - getting taken back to Asgard, which of anywhere in the universe is probably the safest place to be when a pissed-off Thanos is coming for you. No wonder he’s in the mood to celebrate at the end (and that may be the scene that gives the most evidence thatsomething is going on with Loki beyond the obvious, because his relaxed little shrug of resignation is completely unlike his manically malicious attitude in the rest of the movie; he’s like a different person, once the heat is finally off.)
Now all Loki needs to do once he’s back on Asgard is get out of his gag and chains, grab the Tesseract and maybe the Infinity Gauntlet while he’s at it, and then, having obtained ultimate power, make like a proper Loki and do what he wants. Probably take out Thanos, take over some realm or other just ‘cuz, and then take a long nap. And maybe stop by the new Avengers tower to take Tony up on that drink…
