The plot.
The movie opens on Thanos , he is on Titan 2 and he's very happy that he performed the Snap then flashes to Tony stark stranded in space. Nebula walks in and says that they are running out of oxygen fast. Tony records his message to pepper potts and then after he's done he gets a sudden burst of inspiration and he begins to try and fix the ship so he can make it back home .
Right after this the title card with the Avengers logo comes on .
Back at Earth at the Avengers headquarters Banner ,cap, Nat, and Rhodey are taking about Thanos when they hear a knock on the door , its agent Klein from shield with Nick Fury's pager . He gives them the pager and tells them that Nick Fury is gone. Banner then takes it and analyzes it, finding that its sending a signal but its losing power . Nat and cap go and have a talk about everything and then Steve and Rhodey go to a snap support group . banner and Nat talked about the Hulk , banner once again tries to bring the hulk out but the hulk again refuses .
captain Marvel eventually shows up at the Avengers headquarters asking where's Fury . the Avengers at the HQ fill her in on everything that has happened with Thanos and the infinity Gauntlet .
Tony stark and Nabula managed to fix the ship and get to the nearest jump point that takes them back to earth.
There's a tiny reunion with the avengers and tony stark and pepper potts but its short lived because tony needs medical attention . All the avengers except for Bruce and tony start talking about what they can do . Nabula says that she knows where Thanos is and then rocket pinpoint an energy source that matches the infinity Gauntlet . The avengers go to Thanos to fight him but are easily defeated . Thanos holds captain Marvel by the neck but Thor saves her ,she is depowered a lot . Thor uses Stormbreaker to bring them back to earth where banner is treating tony .
Banner goes over to a weakened captain marvel and ask to scan her and she agrees . Tony and banner look at the result are stunned by it . They decide that they need to try and copy the infinity stones but they realize they don't have the technology to do it .
captain marvel goes with Thor to find his people and rocket stays with banner trying to find a way to time travel .
There's a time jump forward and eventually ant-man comes out of the quantum realm and goes to the avengers HQ and explains to the avengers about the time vortexes . with some time passing Tony , Bruce and ant-man figure out how to time travel , they have also figure out a way how to copy the power of infinity stones . Tony begins to work on a new infinity gauntlet that would be capable of harnessing all of the power of the infinite stones . they decide that they just can't go back in time to take the infinity stones because the effects of altering the past could drastically change the future too much , so the avengers go back in time to copy the infinity stones from each place they remember having seen them . nabula tells the avengers about soul stone on vormir but she tells them that they need to get ready to loose someone they love . captain America says no because they've lost too many already . so they make a plan to go and fight past thanos on vormir.
Banner , tony , Thor and captain America go to fight past thanos and thor nearly defeats thanos but then thanos uses the power stone on him . Tony uses a new device from his new iron-man suit that stunts thanos for a minute so that banner can copy the stones , he does and they get out of there.
meanwhile present thanos finds out about their plan and goes to the avengers HQ. when the avengers are exiting the quantum realm , he is there waiting with his outriders . thanos is in raged and he start his attack , thor and captain marvel defend the stark gauntlet with everything they have , during this attack Bruce banner finally becomes the hulk and he goes for thanos , thanos uses the mind stone on the hulk and tries to make him turn on the avengers but the mind stone ends up merging the two , and the hulk attacks him . thanos and the hulk go at it, and thanos almost defeats the hulk but Thor jumps in to help . the rest of the avengers in and attack thanos as well but thanos uses the infinity gauntlet to defeat the avengers and to destroy stark infinity gauntlet . thanos then stomp on the avengers logo and gives them a speech on why he did the snap, but in the middle of thanos's speech war machine blasts him with a protons cannon and then thanos uses the space stone to retreat.
Tony realizes that his infinity gauntlet is now destroyed but Howkeye says that he has track down some ARU metal . Howkeye tells the Avengers where it is, so the Avengers go to where it is, defeats some arm dealers who have it and take the ARU metal from themselves .
Tony takes the metal back to the Avengers HQ and forges a new infinity gauntlet . the Hulk wields it and uses it to bring all of the fallen heroes back but losses his arm in the process .
Tony build hulk a new arm and tells them all that they must go fight thanos whatever the cost , whatever it takes .
Dr. strange teleport them all to where Thanos is and than its everybody vs Thanos .
Thanos using the infinity gauntlet still manages to hold everybody but then Thor using stormbreaker manages to cut off thanos's arm , captain America runs to it, grab it puts it on then teleport thanos somewhere before the infinity gauntlet's power kills him.
The movie ends with captain America's funeral and tony gives a speech. after funeral tony hands Bucky captain America's shield and Bucky on the mantle of captain America .
Howkeye finally retires and he leaves with his family leaving his bow behind.
Thor goes to rule over his remaining asgardian in Norway .
Bruce banner says that he needs to leave to leave to find more about his new powers being merged with the hulk now.
Black widow leaves saying that she has some unfinished business to attend AND captain marvel will assemble the rest of the heroes .
Dr. strange is left with the infinity gauntlet and takes it back to the sanctum sanctorum .
