Glass is ahead of the group, following deer tracks. It's risky (i.e., noisy) to use guns to hunt, but it's a risk they have to take. He bursts through some brush, but he doesn't see what he expects…
Instead of deer, he sees two bounding bear cubs. Aw, cute. Suddenly, he hears a crushing sound about fifty yards away, moving closer. Then he sees it: the mama bear.
Glass knows that he only has one shot, so he carefully takes aim at the bear's heart. It hits, but "her attack did not slow" (1.3.15). Oh, that's great.
The attack is gruesome—pretty much how you'd expect a bear attack to go down. Glass falls into unconsciousness.
Meanwhile, Black Harris hears Glass's shot and rushes to his location. He finds a strange scene: the cubs, mewing, and the giant mama bear, lying dead on her belly. Guess Glass's shot hit, huh? Black Harris shoots one of the cubs.
Captain Henry and company hear both shots and hurry upstream.
Harris finally sees Glass's body. Or, more accurately he sees his arm—the rest is unhelpfully buried underneath the giant bear.
Harris gives a few tugs and frees Glass. And boy, is he messed up. His scalp is basically off his head; his throat has three gaping gashes from which blood bubbles; and his back is torn to shreds.
That's when Henry and the rest of the group approach. They try to clean Glass's wounds, which wakes Glass up a little, though he still can't speak or move much.
Bridger leads the charge to patch up Glass. There's one thing he can't do, however: stitch up the wounds. Captain Henry takes care of that, kind of haphazardly.
After he finishes, Henry goes to the river to clean the "sticky blood" from his hands (1.3.56). He's freaking out—the expected death of Glass, one of his best men, makes him feel cursed.
Meanwhile, the men are butchering the bears while Bridger tends to Glass. Seeing this, Glass chops off one of the bear claws and puts it in Glass's bag.
The attack might be a bummer, but the crew is psyched to have a fresh, warm meal. After they finish, Henry goes scouting and tells the crew to dig a grave for Glass before he gets back.
Henry returns, but there's no grave. When he asks why, Harris explains that the dude just isn't dead yet. Whoa. The next morning is the same story.
With nothing else to do, Captain Henry orders that a stretcher be built so they can carry Glass along with them.