E! News has an exclusive look at Paul Bettany, Chadwick Boseman, Josh Brolin, Chris Evans, Danai Gurira, Chris Hemsworth, Scarlett Johansson, Anthony Mackie, Elizabeth Olsen and Sebastian Stan filming the devastating finale, culminating in—spoiler alert!—Thanos activating the Infinity Gauntlet and snapping his fingers, wiping out half the galaxy’s population.