Whoa! Tony Stark had dropped Avengers 4 title in Age of Ultron in 2015 and we didn't notice

The over two-minutes-long trailer was released by directors Russo Brothers-- Joe and Anthony-- on their official Twitter handle. 

"For those who have been here since the beginning. For those who have joined along the way. For the best fans in the Universe. This trailer is for you...," they captioned the post. 

The trailer is set after the destructive battle of Wakanda in which Thanos wipes of half of the population and has left Marvel superheroes Iron Man (Robert Downey Jr), Captain America (Chris Evans), Thor (Chris Hemsworth) and Black Widow (Scarlett Johanasson) scrambling for a way to defeat the supervillian from Titan. 

While there’s speculation that it was Benedict Cumberbatch’s Doctor Strange who said the words in Infinity War when he said: “We're in the endgame now.”

However, it was the other Sherlock actor – Robert Downey Jr’s Iron Man who actually uttered the words first.

In Avengers: Age of Ultron, while trying to justify to his fellow Avengers why he had created a murderous superbot, Tony explained: “We're the Avengers," he says. "We can bust arms dealers all the live-long day, but that up there — that's the endgame."  

tony said it in age of ultron first pls stop quoting strange pic.twitter.com/L10b4EmH35

Marvel Studios has given out very less details considering numerous theories surrounding the film, but definitely promises to give its fans one of the darkest superheroes stories they have ever seen on the big screen.

The trailer, which stars with IronMan recording an audio message as he remains lost in the space following his fatal encounter with Thanos at Titan, goes on to share the pain other superheroes are going through as they face a partial defeat. 

AntMan (Paul Rudd) and Hawkeye (Jeremy Renner) have finally made it to the trailer after much speculations about their appearance in the film. Both the characters were missing from "Infinity War". None of the "Guardians of the Galaxy" characters, apart from Nebula, were part of the trailer. 

Captain Marvel (Brie Larson), whose name was introduced in the post-credit scene of "Infinity War" and is expected to play a major role in defeating Thanos, is still not part of the trailer. The standalone "Captain Marvel" film is set to be released on March 8, 2019.

"Endgame" marks the final film within the Marvel Cinematic Universe's current generation. It comprises 22 films, including "Spider-Man: Homecoming" and the upcoming "Captain Marvel".  The film will release on April 26, 2019.