The tense footage appears to show the Avengers crew getting tooled up to go and face the intergalactic baddie, Thanos, with Captain America giving a rousing speech to get his team pumped up for the battle of their lives.
During the montage, Cap can be heard saying: "You know your teams, you know your missions. No mistakes, no do-overs. Look out for each other. This is the fight of our lives."
Ooooo, exciting stuff, right?
Well, fans seem to think so and have been commenting on the clip saying so.
One person wrote: "My hype for this can and will never be trumped."
Another put: "Iron Man will kick ass of Thanos!"
This is the latest in a series of clips to be released of late. Earlier this week, the very first snippet of footage from the film premiered on Good Morning America and featured a conversation about the best way to bring back the fallen Avengers who were taken in 'the snap' that destroyed half of all living creatures in the universe, in the last film.
To say it's emotional is something of an understatement.
And fans have been falling over themselves to be among the very first to see the film that will bring the curtain down on this chapter of the Marvel Cinematic Universe - the 'Infinity saga' - which began with Iron Man, way back in 2008.
Some are so desperate, they have been forking out thousands - $15,000, to be exact - to get their hands on just one of the elusive tickets.
And no, that kind of money doesn't mean you actually get to meet Iron Man and the rest of the gang. Oh no.
What it does get you, however, is a seat at the AMC theatre in West Orange, New Jersey. Money well spent, I think you'll all agree.
Well, if the Marvel boss is right, it definitely is. CEO Kevin Feige says the fourth instalment of the comic book franchise is so action-packed, you can't even afford a couple of minutes for a slash.
Avengers: Endgame will hit cinemas from 25 April.