Simon breathes in to blow out the candles, but suddenly the lights start to flicker out on the ship. Jayne asks what that was. Kaylee thinks it was just a little "hiccup," but says she'll go to the engine room to take a look. Wash says he'll head up to the helm to make sure everything's okay up there. River says, "Fire," which Simon thinks is a reminder that he has to blow the candles out. He starts breathing in again, but it turns out that's not what River meant at all. As Kaylee starts heading toward the engine room, a huge ball of flame tears down the corridor toward her. Zoe sees it and reacts first, rushing over and pushing Kaylee out of the way. The blast of flame throws Zoe back into the table. Wash sees this and panics. River shouts, "Fire!" over and over again. Inara and Book rush over to see if Kaylee is okay. Wash and Simon rush over to Zoe.
Mal rushes over and seals the corridor. Then he runs out through another corridor, ordering Jayne to seal everything that leads below decks. Mal heads up to the bridge and flicks some switches that cause the cargo loading door to start opening. Simon looks over at unconscious Zoe, but needs his medical kit to figure out her condition. He tries to run down a corridor to his medical bay, but Jayne blocks him. That part of the ship is sealed off. Simon says that if he doesn't get his kit, Zoe could die. Jayne explains that if he lets Simon through, they'll all die. And the reason for that is because Mal is putting out the fire by sucking all the oxygen out of the lower deck into space. We watch as a snake of fire zooms through the corridors and get dragged out into space by the power of vacuum. It looks cool. Totally fake, but still cool.
Cut back to blue-tinted Mal of the present. He stumbles down some stairs, holding the widget, and opens a door to a corridor.
This prompts a shift back to the accident. Zoe is brought into the medical bay. Simon determines that she hasn't been burned, so the injuries must be internal. He putters around, doing medical stuff, while Wash begs Zoe to wake up. Mal sees Kaylee outside the bay and heads over to talk to her. Kaylee is just staring at Zoe. Mal tells Kaylee that he needs her to go to the engine room to figure out what's going on. Kaylee observes, "She ain't movin'," but she's referring to the ship, not Zoe. Mal repeats to her in a comforting manner that this is why she needs to go down to the engine room to figure out the problem. She agrees, and rushes off.