The Marvel Cinematic Universe is notorious for studio micromanagement: every facet of every movie is pored over and approved by the powers that be, including super-producer Kevin Feige, who usually represents the final word on most subjects.
Given that this is the case, it remains surprising that so many plot holes continue to slip through the net. That may be a function of the complexity of the universe, of course - over the last thirteen years we’ve had two dozen movies and a growing number of television shows, all of which share the same world and the same narrative continuity.
Now, for the contrarians amongst you, let’s establish a few ground rules. Plot holes are defined as inconsistencies that fly in the face of the story being told. Plot holes could include incidents that don’t follow on from one another (“a minute ago he couldn’t walk, now he’s climbing up drainpipes?”); gaps in internal logic (“but they literally just said that her powers don’t work that way!”) ; or even gaps in ordinary logic (“okay, he’s a smart dog, but he still can’t operate an iPhone”).
Of course, if you look hard enough or for long enough you can find inconsistencies in any movie. However, a real plot hole is one which is so nonsensical that it affects your suspension of disbelief, taking you out of the story (even if only for a few moments)...
10. Just How Many Stones Does Thanos Have Before Infinity War?
In The Avengers, set in 2012, Thanos sends Loki to obtain the Tesseract (containing the Space Stone) and subjugate Earth, giving him the Sceptre (containing the Mind Stone) and a Chitauri army to help accomplish this task.
There’s a lot of lazy writing going on in The Avengers - for example, it’s never explained how, when S.H.I.E.L.D. fiddles with the Tesseract and opens a random wormhole, Loki is at the other end. It’s also never made clear why Thanos gives Loki - a newcomer to his forces with a reputation for untrustworthiness - the only Infinity Stone he’s managed to obtain so far.
However, although plot holes are always due to lazy writing, lazy writing isn’t always a plot hole - so let’s look at the Thanos we meet in act two of Avengers: Endgame, during the Time Heist. Because the plot mechanic is time travel, the movie establishes that it’s 2014, the time period of the events of the first Guardians Of The Galaxy movie. The Infinity Stone being sought by his forces on the planet Morag is the Power Stone, just as it was at the beginning of that film.
So why do Gamorra and Nebula, in discussing their father’s plans, make it very clear that this is the first Infinity Stone Thanos has managed to find?
Nebula: “Father’s plan is finally in motion.”
Gamora: “One stone isn’t six.”
Nebula: “It’s a start. If he gets them all...”
Remember, this isn’t an alternate universe, it’s a single, coherent timeline, two years after The Battle Of New York. By 2014, he should have already found the Mind Stone and the Space Stone - he knows they’re on Earth, at the very least - so this should be the third Infinity Stone he’s found.
By this point, Thanos is only a couple of smash n’ grab raids away from being halfway to his genocidal objective. His plan has been in motion for years.