NEW YORK • No spoilers here, Avengers: Endgame directors have revealed the secret to their marvellous box-office success.
To hear Anthony and Joe Russo tell it, the triumph stems from a few key ingredients, including social media buzz and a serialised approach to film-making.
But the rise of streaming services also helped, according to the brother duo, who oversaw Endgame and other blockbusters for Walt Disney's Marvel Studios.
Despite fears that Netflix and other online platforms will depress movie attendance, the services can help get fans excited about franchises - and get them into theatres.
"They're supercharging one another," Joe, 47, said of video streaming and the film business. "There's just an addiction to content consumption. This generation is craving a new kind of storytelling."
The brothers spoke on Monday on a panel at the Milken Institute Global Conference in Beverly Hills, California. They have directed four Marvel movies, including Captain America: The Winter Soldier (2014), which took the super trooper out of his frozen past into the modern age.
With Captain America: Civil War (2016), they persuaded Iron Man actor Robert Downey Jr to be a bad guy for a bit, leading to superhero infighting and a loss at the end of last year's Avengers: Infinity War.
"You have to take chances," Joe said. "You have to surprise the audience. They'll tell you they like chocolate ice cream. If you give it to them 15 times in a week, they won't."
The brothers have 1.7 million Instagram followers and like to drop nuggets about their projects.
Joe said: "We put clues that are inscrutable. We don't respond directly to fans, but we put information out there they can have conversations about."
Movie studios used to stagger releases in countries around the globe, due in part to varying holidays and school schedules.
Endgame came out in nearly all its major markets at the same time, creating a global event that got people talking in advance and attending theatres in groups.
"It's critical because of that collective experience," said Anthony, 49.
''It can feel a little like a rock concert. The crowds are so vocal. That's a whole dimension to the experience that can't be achieved at home."