We may not have the exact details of what will go down in Avengers: Endgame, but we’re reasonably confident that we’ll see time travel in the movie. One or more characters will have to journey to the past to prevent Thanos from killing half of all living things in the known universe. So far, we saw plenty of proof to back up that theory, including leaked photos from the Avengers 4 set that showed several Avengers actors working on scenes that were set during the New York battle from the first Avengers film. We also saw plenty of toy leaks that revealed several Avengers will ditch their regular costumes in favor of special suits that will help them travel to the Quantum Realm.

The most recent toy leak gives us a great look at Thor and Hulk in those suits, while revealing that other Avengers will also join them. With that idea in mind and with the knowledge that time travel is a big part of Endgame, you should check out the following fan theory about the upcoming Marvel movie.

Reddit user fishgrey explains that Dr. Strange’s plan to defeat Thanos is to help Tony Stark build an Infinity Gauntlet-like weapon that would allow the Avengers to win. For that to happen, Strange will send two of the Infinity Stones forward in time to Stark, so the tech genius can learn all of their secrets and create a suit or weapon that can ultimately be used to wield the stones against Thanos and avoid the snap.

To set things in motion and to make sure events play out in a particular order, Strange would have to make sure that Tony survives that battle on Titan, the theory says. Also, Strange would contact Loki in the past at some point to obtain the Tesseract from him. The Tesseract has the Space Stone in it, so he can remove it and send it to Tony:

I believe at some point after Dr. Strange uses the time stone to see 14 million future outcomes, Strange contacts Loki (in the past, via time projection) and explains the imminent danger and his plan to reverse it. (He contacts him either during Infinity wars opening on the Asgardian ship [During Infinity War, Strange contacts Loki during the fight on the Asgardian vessel explaining his plan and prompts Loki to attack Thanos to stall him], or in during/before Thor: Ragnarok [Before Infinity War during Ragnarok, this is why Loki goes out of his way and slightly out of character to grab the Tesseract as they needed it for Strange’s plan.])

Once Tony had completed his study of the Stones, the theory says they would be given to Thanos to avoid a time paradox:

So meeting with Loki before he died, Dr. Strange explained his plan (hence Loki’s bold statement to Thor). The stones were sent forward in time to Tony to allow him to study the Stones and build his own suit or gauntlet to wield them (we know a leaked Lego set for Endgame is of Tony’s build/suit room) once he has completed this, the stones return to Loki and Strange as we see in Infinity War and are thus given to Thanos to avoid a time paradox. This could be why Loki summons the Tesseract in the same way Strange summons the time stone as it is reappearing from the future into the present.

Using the new weapon, the heroes would then embark on a quest to gather the stones and reverse the snap. It’s unclear where they’d collect the stones from, though. But the odds are fairly good that they might have to go back in time to retrieve them.

The Redditor also suggests other ideas that would work together with the theory above. For example, he says the Quantum Realm particles that Ant-Man gathered at the end of Ant-Man and the Wasp may help Tony wield the Stones in some manner. Also, the theory says that Doctor Strange may contact Ant-Man while he’s inside the Quantum Realm after the snap, in order to explain the plan. Thanos may be trapped in one of Strange’s time loops while all this happens, with Ant-Man being the only one able to escape it thanks to the Quantum Realm.

Finally, the Redditor has also come up with an idea for a great final battle scene between the heroes and Thanos:

I’m dying to see Cap in a epic final scene wielding Mjolnir in one hand (We know time travel of some kind is present in Endgame, so perhaps Mjolnir will have a cameo) and his shield in the other, or even better Iron Man in his new suit embedded with the stones, wielding Mjolnir (Using the power of the Infinity Stones) whilst defending himself with Cap’s shield in the other hand!

Endgame hits theaters on April 26th, so you have plenty of time to check out the full theory below while we wait.