Those are the terms that Avengers: Infinity War co-director Joe Russo put it into when asked about the past and future of the Marvel Cinematic Universe during a press event.
"If Marvel's been writing a book for the past 10 years with these movies, Infinity War is the final chapter of that book," Russo said. "Then there'll be a new book written, and that will be the next phase of Marvel."
Avengers: Infinity War writer Stephen Mcfeely has spoken about the film in similar terms.
"This is about the culmination of the Marvel Cinematic Universe," McFeely said during a press visit to the Avengers: Infinity War set. "This is about everyone getting together, or trying their hardest to get together, to fight a guy named Thanos. We've been teasing Thanos for many movies in 30-second clips, so hopefully all the lead up will allow us to really go to town with him and make him a villain that requires this epic level of storytelling That is the word I would use most often. It's ridiculously big."
Russo's statement may leave some wondering how Avengers 4, which is still officially untitled to the public, fits into the Marvel Cinematic Universe library. Joe Russo's brother and co-director, Anthony Russo, made it clear that Avengers 4 is its own film but that it will complete the story that the Russos began with their first Marvel Cinematic Univers movie, Captain America: The Winter Soldier.
"That was our intention," Anthony said in the interview. "Joe and I always looked at it in the same way we presented Winter Soldier as a complete film, Civil War as a complete film, but there was a narrative thread that connected them. Civil War pushes forward to Infinity War, Infinity War pushes forward into the fourth Avengers movie. So there is a narrative thread, but we wanted them to be their own unique impressions."
Avengers: Infinity War releases on April 27th. Other upcoming Marvel Cinematic Universe movies include Ant-Man and the Wasp on July 6th, Captain Marvel on March 8, 2019, the fourth Avengers movie on May 3, 2019, the sequel to Spider-Man: Homecoming on July 5, 2019, and Guardians of the Galaxy Vol. 3 in 2020.