Avengers: Infinity War was released in April of 2018. It was a box office hit. It seems pretty unlikely anyone wanting to know what happens in that movie is still unaware, but if so...
SPOILERS
In Infinity War a gigantic purple space-alien villain named Thanos is seeking out these things called Infinity Stones to put in this giant metal glove he is wearing called The Gauntlet. The Avengers try to stop him, but ultimately he succeeds in collecting all — how many of them are there, like six? Let’s go with that — six stones.