The story begins with Thanos and his army attacking Xandar, where the Nova Corps is guarding one of the Infinity Stones. The Avengers, consisting of Iron Man (Robert Downey Jr.), Doctor Strange (Benedict Cumberbatch), Spider-Man (Tom Holland), and the Guardians of the Galaxy (Star-Lord (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista), Rocket (voiced by Bradley Cooper), and Groot (voiced by Vin Diesel)), team up to stop Thanos.
The "Snap" (or the Decimation ) resulted in the literal dust-to-dust disappearance of fan favorites like Black Panther, Spider-Man, and Scarlet Witch. It left the survivors—and the audience—in a state of genuine grief and uncertainty that lasted until the release of Avengers: Endgame a year later. Why It Matters Today The Avengers - Infinity War