Everything??!
Well...
Hawk eye loses his entire family after the click and turns in to a bit of a vigilante killing cartel members and other baddies because he's annoyed that the are still alive and good people have died.
Captain Marvel saves Tony from space. Tony is mad and doesn't want to help so everyone else gets together to do something.
They then all fly off to get Thanos with the help of Nebula.
They find Thanos but he's in bad shape because he's destroyed the stones.
Thor chops his head off.
They then flash forward 5 years. All of Ant Mans things are in storage and he is released from the quantum realm.
He finds Captain America and Black Widow and tells them that he was stuck for five years but to him it was five hours so maybe time travel is possible to get everyone back.
They find Tony Stark who has since had a daughter and tell them they need a time machine of sorts building. He says no.
They ask Bruce Banner who is now just friendly Hulk who agrees to build it. They try but it doesn't go smoothly. Tony has came around to the idea after developing a machine that will work.
They go back in time and there are quite a few twists and turns. Biggest things are Loki manages to escape at some point (which will lead to him having his own series I think) and Black Widow sacrifices herself so that Hawk Eye can get the soul stone. Anyway they manage to get all the stones and bring them back to present day. Or 5 years ahead. I'm not sure when it's set.
They put the stones together and hulk wears the gauntlet and clicks.
Thanos from the past gets wind of what is happening and comes to earth to stop them. It's not looking good and there's quite a big fight. It's not looking g good but then suddenly everyone is back. Cue lots of crying from me. Also whilst time travelling Thor (who is now fat and a bit of a mess) gets his hammer as well as still having storm breaker. Whilst fighting Thanos Captain America manages to pick up the hammer which is amazing!
They all start fighting and it's looking better but then Thanos manages to get the stones. He clicks but then realised he's got the wrong glove on. He sees iron man with the glove. Iron man clicks and then all the baddies that Thanos brought with him turn to dust as does Thanos.
Tony Stark does because the stones are so powerful. He has a funeral and everyone goes to it.
Captain America needs to go back in time again and put the stones back. He doesn't come back to the present day like he's supposed to but goes back to be with Peggy.
At the end he's sat on a bench as an old man and he gives the shield to Falcon. Then we see him dancing with Peggy as a young man again.
At the end there isn't an end credit scene. But there is a clanking which is supposed to be the sound of Tony Stark making his first costume in that cave (apparently)