Could it be true?
One year after "Captain America: Civil War" and four years after "Guardians of the Galaxy: Vol. 2". Thanos intercepts the Grandmaster's ship to collect the Space Stone from Loki, who betrays Thor and bargains a position as Thanos' advisor. Thanos then retrieves the Reality Stone from the Collector, killing him in the process. The Guardians of the Galaxy find Thor while investigating Thanos' trail of destruction and learn he has slaughtered the surviving Asgardians. They confront Thanos in Xandar, but he easily cripples the Nova Corps and reclaims the Power Stone. They then go to Earth to ask the Avengers for help.
Captain America, Black Widow, Hawkeye and Falcon have become illegal vigilantes wanted by international authorities. In Scotland, they rescue Scarlet Witch and Vision from Thanos' children, Corvus Glaive and Proxima Midnight, who are after the Mind Stone. They are recruited by Doctor Strange to stop Thanos at Thor's behest, alongside Iron Man, War Machine and Spider-Man. Iron Man is still embittered by the events of "Civil War" and refuses to work with his former friends.
Iron Man, Spider-Man and Doctor Strange head into Space with Thor and the Guardians of the Galaxy to find the Soul Stone, but are defeated by Thanos, who steals it, and return to Earth. The others escorted Vision to Wakanda, where Black Panther has agreed to help them protect him from Thanos' lackeys. The Winter Soldier is revived to help in the battle.
Although the Children of Thanos are defeated, Thanos arrives, reclaims the Mind Stone by killing Vision and causes widespread destruction, with Drax and Hawkeye's family among casualties.
Vision's consciouness survives inside the Mind Gem and helps Scarlet Witch momentarily disable the Gauntlet, allowing Loki to temporarily defeat Thanos, sacrificing himself to do so. With Thanos' return being imminent, the heroes mourn their dead and set out to assemble an army to stand against him or die trying.