The Real Reason Tilda Swinton Reshot Endgame A Year Later

A lot goes into making a movie — especially one in the sprawling Marvel Cinematic Universe — and sometimes directors don't get things quite right on the first go-around. Such is the case for Avengers: Endgame and filmmakers Joe and Anthony Russo, who brought back Tilda Swinton to reshoot her scene over a year after she wrapped on it. 

Swinton, who plays the Ancient One, appears during a pivotal moment in the middle of Avengers: Endgame. When Professor Hulk (Mark Ruffalo), Ant-Man (Paul Rudd), Captain America (Chris Evans), and Iron Man (Robert Downey Jr.) travel back in time to 2012 New York City to retrieve three Infinity Stones as part of their time heist mission, Professor Hulk pays the Ancient One a visit at the Sanctum Sanctorum and asks for her to surrender the Time Stone. Ant-Man, Cap, and Iron Man are off retrieving the Space Stone and the Mind Stone from Loki (Tom Hiddleston) and HYDRA operatives disguised as S.H.I.E.L.D. agents, while Professor Hulk is on the receiving end of a lecture about how one can't just take an Infinity Stone out of its proper place without severely damaging the existing timeline. 

It's an important scene that establishes how time travel works in the MCU – but it's a scene that originally played out differently. 

Chatting with IndieWire, Swinton revealed that the Russo Brothers called her into film the sequence all over again a year after she first shot it. The reason? Some dialogue and a few story elements were altered, as was her Ancient One costume. 

"It was a surprise to me, too! And it was a pleasure," Swinton began, discussing how wonderful it was to have even a small role in Avengers: Endgame. "But what was a real surprise was, we shot it one summer day, and then over a year later, I went back to reshoot it because a couple of lines had been changed, a couple of plot points had been changed. And there was a tweaking of my costume."

As is expected, Swinton couldn't dish up explicit details on what the original take entailed, though she did state that the reworked plot points were "all about that very, very important" visual timeline the Ancient One crafts when explaining to Professor Hulk the rules of time travel and alternate realities. She then noted that the alterations centered around "the information that the Ancient One holds about the nature of the [Infinity] Stones, that they have to be put back."

In the theatrical cut of the film, the Ancient One goes into great detail about how the timeline is impacted when someone takes an Infinity Stone from one point in time and transports it to another. That kind of removal — one that Professor Hulk is asking the Ancient One to allow him to do by handing over the Time Stone she so ardently protects — creates a branch timeline that is dark, chaotic, and doesn't abide by the same laws that the original timeline does. This explanation informs the Avengers' decision to have one team member — Captain America — return the Stones after they defeat Thanos (Josh Brolin) at the end of the film. 

Swinton also laughed that the Russo Brothers changed up the dialogue in her scene to better connect to Avengers: Endgame shooting down time travel rules presented in classic movies such as Back to the Future, Hot Tub Time Machine, and Bill & Ted's Excellent Adventure.

Having to put a temporary pause on all other responsibilities to do something as wild as reshooting just one scene for a movie she filmed over a year earlier might infuriate other actresses, but not Swinton. She gushed about her experience working on Avengers: Endgame, and said that the double shoot was more than worth it. 

"That was amazing, and a whole other world of filmmaking," said Swinton. "But, boy, was it worth it. They tweaked it into something extraordinary."

We may never know that the original version of the Sanctum Sanctorum sequence in Avengers: Endgame was like, but there's little denying that the reshoot added valuable clarity to the film. Without fully fleshing out the brutal consequences that can come when the Infinity Stones are taken and not returned to the points in time they were removed, the time travel elements of Endgame would have been incredibly confusing. Fans have already had a hard time wrapping their head around how time travel works within the context of the MCU — and had Swinton not reshot the Ancient One scene, understanding it all may have been virtually impossible.