Outside, Kaylee takes down a Reaver. Jayne takes a shot but keeps going. I have never seen so many main characters get shot in one ten-minute period except on this show. Kaylee gets some scary-looking darts in her shoulder and goes down. They're dropping left and right. "Fall back! Everybody, fall back! Fall back now!" orders Zoe, and they pull back behind the blast doors, which lie open just a bit. Reavers slavering and boiling, human waste, terribly hungry.
Jayne offers his last grenade. Kaylee offers to close the doors completely -- but can only do it from the outside. "No one's coming back from that," says Zoe. "How much ammo do we have?" Jayne calls it out ("Three, four max. And my swinging cod. That's all." Somewhere, seven thousand people go squee!). Kaylee's losing feeling from the darts. Simon offers to give her a counteractant, then suddenly realizes his bag is still outside. Fucking Simon. I love you, but...are we shocked? That bag is the point of you. He jumps up, unthinking, to retrieve it -- for her, for Kaylee shot and losing vision -- and is shot. River rushes to his fallen body as Jayne fires through the open window. Inara urges her to apply pressure, and Simon stares up at her. "My bag. I need adrenaline. And a shot of calaphar for Kaylee. I can't..." he falls back. "River. River, I'm sorry."
"No." The lights go dead. The sounds of Zoe and Jayne firing into the window become an afterthought. "No," River says again. "I hate to leave..." breathes Simon. "You won't. You take care of me, Simon. You've always taken care of me." She stands, all lit up in the darkness, by a spotlight so beautiful you don't notice it's a conceit. River gives the director and crew -- Joss mentions the gorgeous lighting at every opportunity in the commentary, but especially loves the Expressionism of the River scenes -- license to make you cry with shit like this. "My turn."
She runs, sprints, spots chasing her in the darkness, down the tunnel, flying through the window without stopping. She is being born to a greater purpose. She knows it. She can handle it. In one single movement, River activates the blast door -- no going back -- and tosses the bag through the closing aperture. We see her, pulled like the Helping Hands scene in Labyrinth (again, it's a powerful image, and I can't recap it for you without help) but sideways, into the hell of the seething Reaper mess. The door closes on her beautiful face as she's pulled away, out, down. It's one of the best visual sequences in this or any other fucking movie.