From Empire.
>Thanos is the main character of the movie.
>Thanos sends the Black Order to retrieve the Infinity Stones on Earth while he's searching for the Reality Stone.
>Corvus Glaive and Proxima Midnight attack Vision and Scarlet Witch in Edinburgh, Scotland, for the Mind Stone, but they are rescued by Captain America, Black Widow and Falcon.
>Ebony Maw and Cull Obsidian attack Doctor Strange in New York City to get the Time Stone. The spaceship seen in the trailer belongs to them.
>Iron Man arrives to help Strange ("You can't park here, buddy. Earth is closed today. Take your tractor beam and skedaddle"). He tries to get Bruce Banner to Hulk out and help him, but Banner can't ("Come on, Bruce. Don't embarass me in front of the wizard").
>The movie is not particularly humorous like SPIDER-MAN: HOMECOMING or THOR: RAGNAROK. "The one thing that character deaths do is remind you that the world has real stakes. Death is a real possibility in the storytelling", says Anthony Russo.
>According to the Russos, CAPTAIN AMERICA: CIVIL WAR holds a vital clue to AVENGERS 4. According to them, the movie is "more of an epic adventure in the classic sense, with huge emotional stakes."