Avengers 4: 15 Big Questions From Everything We Know So Far

11. How Will BARF Be Key?

What We Know

On MTV‘s Happy Sad Confused podcast, Avengers 4 director Joe Russo said fans should rewatch Civil War if they are looking for clues about the upcoming sequel:

“Certainly, there is a five minute sequence in Civil War around a piece of technology that was laid in for a very specific reason. If you go back and look at that film, you may get a hint as to the direction.”

His hint is clearly towards Tony Stark's delightfully-named BARF technology, which appears in the opening act of Civil War.

What We Need To Know

How exactly can a technology that Stark says is "an extremely costly method of hijacking the hippocampus... to clear traumatic memories" tangibly affect the plot? Could it be used tohijack Thanos' mind to manipulate him into taking back the snap? Or could it be something more sci-fi than that - like Stark retuning it to be a time travel device?

The latter is unlikely and it could well be that the Russos simply dropped that hint to suggest a reason for the set leaks showing the past will be revisited in Avengers 4. But then again, nothing in the MCU now is added without it paying off and BARF doesn't feel like it really has been yet. So there's definitely something there to be revealed.