Russo Brothers and Robert Downey Jr. on live watching Avengers: Endgame in a time of coronavirus

The Russo brothers and Robert Downey Jr. are traveling back in time.

Taking to Instagram tonight to live-watch Avengers: Endgame a little more than a year after its epic release, Joe and Anthony Russo went down memory lane while also opening up about viewing their Marvel mega-hit in the age of the coronavirus pandemic. And the directing duo got a helping hand from their former star, Mr. Iron Man himself, who offered up his own thoughts from quarantine as their special guest.

"It's strange watching this movie in a time of coronavirus," commented Anthony Russo. "We've all experienced this global crisis, and I think about this movie a lot when I'm walking around the empty streets by my house."

For his part, brother Joe talked about what's changed for them in the year since Endgame stormed theaters and "the shared emotional experience" among moviegoers that made the flick a viral phenomenon on its way to becoming the highest-grossing film of all time.

"It's fascinating when you reach a point in your career that you have ... a story as satisfying as this with an audience," he said. "It will resonate as a career highlight for us for the rest of our lives."

Joining the brothers later on in the webcast, RDJ revealed that he and other Avengers had a mini-reunion a few days ago (we assume via Zoom, and likely to commemorate the shared experience of shooting the Marvel epic) and, in his own deft way, opined on the surreal COVID-19 world we've now entered.

"All time is very strange right now. There's cycles within cycles. It's been fantastic and a lot of introspection. And I won't say why, but I had an occasion to be interfacing with other Avengers five days ago," said Downey Jr. "And when we hang up, I just got this wave of … I'm sure for you it feels like a year ago you worked a thousand years straight."

All that work certainly shows up on screen, and behind the scenes, too, as the Russos' running commentary, complete with pics and vids, marvelously illustrates ...

On the challenge Brie Larson faced filming Endgame before Captain Marvel:

"Brie's first day on set was the actual space ship," revealed Joe at the beginning of the live-watch as viewers saw her character, Captain Marvel, rescue Tony and company in space. "It's tricky to find a character on set when they haven't had a movie about them or centered around them. It's a lot of work for us and a lot of work for the actor, 'cause you need time to play ... it's very difficult for Brie to play a character she never played before, to show up cold on screen … and define her character."

On Josh Brolin adapting to motion-capture-style acting:

"Brolin took to this role like you wouldn't believe," said Joe, discussing the motion-capture outfit the thesp had to don to facilitate his digital transformation into Thanos. "For the first 20 minutes, it knocked him off balance a little bit, and then out of nowhere he grabbed onto it in a way you couldn't believe. He started treating it like a theatrical experiment, like he was in a black box play. And the transformation is incredible."

On subverting the audience's expectations:

Joe weighed in on how the brothers meticulously plotted with screenwriters Christopher Markus and Stephen McFeely to surprise fans at every turn. Case in point ...

"When that [title] card pops up, you think that the movie is gonna be a space movie to stop Thanos," noted Russo. "And then we flip that on you ten minutes later … and that was always our mission with Endgame, was to subvert your expectations and keep surprising you."

On Paul Rudd grounding Endgame emotionally:

The siblings marveled at the Ant-Man actor's ability to deliver all kinds of technobabble and info related to time travel, the quantum realm, the Infinity Stones, etc., in a funny and entertaining way. But he did so in a way that also conveyed real human emotion that allowed the audience to connect with the character and the rest of the Avengers — scenes that were crucial to the Russos' vision.

"The look at [Rudd's] face and the way he's playing such high concept with some grounded emotional life and psychological realism, really that for us was the tone of this movie. We said 'That's it. That's the film,'" said Anthony, commenting on Rudd's character Scott Lang, better known as Ant-Man, exiting the quantum realm and reuniting with his wife post-Snap.

Ditto for Scarlett Johansson, by the way.

Some nice real estate if you can get it:

The Russos also dropped some behind-the-scenes tidbits about the now iconic log cabin along the lake, where Tony's spent the last five years after the Snap — located on a ranch outside of Atlanta where Avengers: Endgame was shot.

"There was a man-made river that we built that was amazing. That was one of the most incredible feats of engineering," exclaimed Joe about the cabin, located on a ranch in Fairburn, Georgia (and which is now available to rent, apparently).

Added Anthony about the importance of the cabin to Iron Man's arc: "I think we all had a lot of fun conjuring a Tony Stark trying to find a new life … 'cause his memory of the old one was so painful."

On the genesis of "I Love You 3000":

Once Downey joined the conversation, he and Joe Russo discussed the moving simplicity of Tony Stark's memorable line to his daughter.

"I thought that was a lovely scene and without that scene the "'Love You 3000' wouldn't be as poignant," said the actor. "It was something my eight-year-old says to me. … it turned out to be really significant. But all this stuff in the movie was about us being able to bring our experience through the years."

He added: "After 20 plus movies, we the audience, our cast and crew, the whole planet was kind of in this resonance with each other, and it was all leading up to this finale."

On Iron Man and Captain America burying the hatchet:

In that beautiful scene after the former frenemies reunite and Tony gives Cap his shield back, RDJ got a little verklempt.

"Awww man," reminisced Downey. "I hand this one to Chris Evans. It was all about him forgiving me for not forgiving him so we can start getting ready to who knows, ya know.  Maybe throw in the towel for what we gotta do… it was burying the hatchet and taking up the cross together."

On shooting that "long take" with Hawkeye, aka Ronin, fighting Akhido in Tokyo:

"This was a oner we conceived with Renner," said Joe. "This was one that we just thought was very important for his character and get a sense of … how violent he had become and self destructive." 

On their future in the Marvel Cinematic Universe:

Joe: It was an amazing experience both creatively and emotionally, so we're always looking for stuff to do together and it's just a question of timing and the right thing to do together."