Avengers: Endgame complicates its internal logic by breaking its rules of time travel depending on the needs of the story.

Warning: There are massive spoilers for Avengers: Endgame ahead. Do not read this if you haven't seen the movie.

Evading the Internet's accidental leakers and party poopers is never easy. In a desperate attempt to steer clear of Avengers: Endgame spoilers, some of us had to quarantine our Twitter feeds and WhatsApp group chats, and virtually go off the grid for three whole days.

But boy, was it worth the wait! Avengers: Endgame was a deeply cathartic conclusion to Marvel's Infinity Saga — and a fitting tribute to the fans, who have been invested in this unprecedented cinematic journey for 11 years and 22 films. From stunning action set pieces to snarky repartee, from heart-warming reunions to awesome tag teams, and from metaLOLs to teary goodbyes, Endgame had them all. As they resolved the cliff-hanger from Infinity War, the Russos offered moments of genuine emotional depth. With its various callbacks, the film also evoked iconic moments from MCU’s back catalogue. It was an incredibly rewarding payoff with fan service of the highest degree.

Yet, as you walk out of the theatre, there's an internal conflict between the fan and the critic. The latter soon takes over and begins to question the inevitable paradoxes, internal inconsistencies and temporal anomalies that tend to creep into any story with time travel as a key plot element. Filmmakers have often dreamed up scenarios where characters travel through inter-dimensional wormholes, space-time vortexes and time machines to edit their own universe and reality. Despite formulating clear pre-established rules for the concept, filmmakers invariably end up in a black hole of their own making. These paradoxes and the resulting plot holes is what make time travel an extremely difficult plot device to pull off.

After the doomsday climax of Infinity War, it was pretty much a foregone conclusion that many of the fallen heroes (whose films are already confirmed in MCU’s upcoming slate) would be brought back in Endgame. Many Redditors had already suggested time travel and the Quantum Realm will play a key role in undoing Thanos' Snap. In the film, Scott Lang suggests the use of Pym Particles to shrink themselves to subatomic size and enter the Quantum Realm. With some scientific mumbo-jumbo theory (involving quantum mechanics and "reverse mobius strip"), fancy little watches and slick new outfits, Tony Stark then figures out a way to help the surviving Avengers travel to various points in the MCU timeline to retrieve the Infinity Stones and reverse the deaths of half the universe.

In most time travel-based films, including Back to the Future and the Bill & Ted movies as jokingly referenced in Endgame, changing the past can dramatically alter the future. In Endgame, as Banner and the Ancient One note, changing the past doesn't alter the future but it instead creates a parallel universe or a divergent timeline. But Endgame complicates its internal logic by breaking its own rules of time travel depending on the needs of the story.

Here are some pressing unanswered questions about Endgame.

Cap sat on a bench reflecting on existence?

If changing the past creates an alternate timeline, how does Steve Rogers — who apparently stayed back and lived a full life with Peggy Carter in another timeline — end up on that bench at the appropriate time in the main MCU timeline?

How does Nebula have access to her future memories?

If changing the past does not alter the future, how do the memory banks of Good Nebula (from the present) and Evil Nebula (from the past) integrate and reveal to Thanos the Avengers' plan to steal the Stones before a repeat Infinity War?

Spider-Man: Far From Logical?

The trailer for Spider-Man: Far From Home sees our friendly neighbourhood superhero embark on a Eurotrip with his pals. We know Far From Home takes place almost immediately after Endgame in 2023; yet, they have all somehow not aged a day in five years. Endgame suggests all those who were Snapped return exactly as they were before they disappeared in 2018. So, it makes sense that Peter Parker will be five years younger than his UnSnapped peers. But the trailer shows all his classmates (including Ned, MJ, Flash and Betty Brant) are still attending high school and haven't aged either. Does this mean they all got Snapped?

Where did Loki go with the Tesseract?

Tony, Cap, Ant-Man and Hulk go back in time to the aftermath of Loki’s Chitauri invasion in 2012 to retrieve the Sceptre and Tesseract (which contain the Mind and Space Stones respectively). But the Tesseract gets knocked out of Tony's hand and the apprehended Loki picks up the Tesseract amid the chaos and does a disappearing act with it. Considering this is the 2012 villainous Loki, and not the 2017 anti-hero we have all since come to love, shouldn't the Avengers be a little more concerned about the timeline they may have doomed? Also, where did Loki disappear to and what sinister plan does he have in store?

Did 2023 Thor leave 2013 Thor hammerless and defenceless?

Meanwhile, when Thor goes back to The Dark World of 2013 to retrieve the Aether (Mind Stone), he steals the Mjolnir from that timeline. While it sure is fun to see Thor armed with both his beloved old hammer and the all-new Stormbreaker in Endgame, isn't the Thor from the new 2013 timeline pretty much screwed? How is he going to protect Asgard from threats like Malekith, Hela and possibly Loki?

How does one deal with Post-Snap Stress Disorder (PSSD)?

Even if one half of humanity perishes, won't the other half eventually learn to let go and look to survive? Life would have eventually returned to some sort of normalcy — even if it is a new normal — and it is unlikely humanity will just give up and let the world turn into a post-apocalyptic wasteland, like we see in Endgame. We see Captain America lead a post-Snap support group where a guy (played by Endgame co-director Joe Russo) opens up about the pain of losing his partner and describes his most recent date. This is the only hint we get of the human race moving on.

Doctor Strange, was there really "no other way"?

Out of more than 14 million possible scenarios, how could this possibly have been the only way to reverse Infinity War's events? So, Doctor Strange foresaw every single event in these timelines, from the calculated to seemingly random, big or small, and found only one future where the Avengers successfully defeated the Mad Titan? What are the odds of that? (1:14,000,605).

And who knew a damn rat would be the saviour of MCU? So, if that rat hadn't scurried over the right button on the control panel in Hank Pym's van, would Endgame have essentially been “The Leftovers meets MCU” kind of story?

How did Hawkeye survive the Infinity Saga?

Having lost his home, family and most of his Asgardian people, the remorseful Thor deals with his PSSD by turning to alcohol and video games. Black Widow never gives up, coordinating what's left of her only family to avenge the fallen? Cap runs a grief counselling session for the survivors. And Hawkeye, the once-devoted family man, goes full dark, gets an edgy new mohawk and sleeve tattoo, and embarks on a murderous rampage.

Clint Barton has now survived the catastrophic events of four Avengers films and a Captain America film against all odds. While the Power Stone damn near killed the Guardians of the Galaxy, he was able to wield the Soul Stone quite coolly in his hand. Maybe, the Soul Stone is not as crippling as the Power Stone or may be Hawkeye is the luckiest SOB in the MCU.

Black Widow vs Hawkeye: Was it suicide or sacrifice?

Speaking of the Soul Stone, the condition to obtain it seems to be pretty elastic. "In order to take the stone, you must lose that which you love. A soul for a soul," says the Red Skull. Black Widow and Hawkeye don't really love each other, do they? They like each other, care about each other too. But love?

Let's say they do love each other. Don't you still have to sacrifice the person you love, rather than the "Let's see who will fling themselves off a cliff first" contest they indulge in? That's essentially suicide, not sacrifice. Isn't it?

Do you really need to be worthy to wield the Mjolnir and Stormbreaker?

In one of the most memorable scenes in Avengers: Age of Ultron, the heroes take turns trying to lift Mjolnir. Tony, Clint, Rhodey and Bruce all fail in their attempt and can't even move it by an inch. But Cap makes it budge a bit before giving up, drawing a brief look of concern and then relief from Thor. But Endgame saw Cap not just lift the hammer but spin it like a pro. Of course, one has to be worthy, not just strong, to wield the enchanted war-hammer. But what changed between Age of Ultron and Endgame that made Cap worthy of it? Taking the right stand during Civil War? Was it the right stand though?

Did Thanos seem stronger yet strangely diminutive without the Infinity Stones in Endgame?

One of the issues with MCU is there is never any consistency in terms of the powers and abilities of its various characters. While Scarlet Witch is surely a force to reckon with in the comics, she doesn't really have the same power level as Thanos in MCU. Yet, she incapacitates the Mad Titan and strips him of his armour. Interestingly, Thanos — even without the Infinity Stones — mounts a serious challenge to Thor and Captain Marvel — two god-like beings. Yet, in Infinity War, Thor came real close to defeating the Mad Titan — armed with all six Infinity Stones — by severely wounding him in the chest.

In Endgame, Thanos — without a single Infinity Stone in his possession — is able to take on Thor, Iron Man and Cap simultaneously. Perhaps, you could argue that Thor "Big Lebowski" Odinson had some fitness issues. But Cap was still spinning the Mjolnir and raining lightning down on the Mad Titan like he was an Asgardian God. And Iron Man ain't no slouch either.

Did Captain Marvel have more pressing concerns than the end of the human race?

When Tony and Nebula are lost and adrift in space on the Benatar with no food, no fuel and soon no air, Captain Marvel magically shows up and saves them. And saves them how! She literally carries them home. She's that powerful. Yet, she keeps disappearing only to reappear whenever the Avengers are in dire need of help.

When the Avengers are on their time-heist mission, they could have clearly used her. But she is nowhere to be seen until the film's climactic battle. Did they lose the pager? Surely, they should have upgraded and given her some sort of a beacon to alert and ask her for help?

In the lead-up to Endgame, everyone assumed she would be the key to defeating Thanos. While she does single-handedly destroy the Mad Titan's spaceship and plays a major role in preventing him from performing Snap 2.0, you wish she had a larger presence throughout the film.

Here are some other not-so-pressing unanswered questions about Endgame.

Do both Obadiah Stane and The Big Lebowski exist in the MCU? If The Falcon is Captain America, is Pepper Potts the new Iron Man Woman? Did Valkyrie's winged horse survive Endgame? Will Luis do a flashback recap of the Infinity Saga in Ant-Man 3?

If Back to the Future’s time travel plot is a bunch of bullsh*t, what does that make Endgame's?