Kaylee starts cleaning up some plates, and Simon offers to help. Kaylee insists that Simon sit back down, because it's his turn to tell a funny story about being a doctor. Jayne observes, "Because sick people are high-larious." And on ER, they're also barometers reflecting the lives of the doctors. Simon gets about halfway through his story about some guy he treated in the emergency room, when our favorite man-ape gone wrong interrupts him to ask Inara if she's got any interesting "whorin' stories." Simon gives Jayne a priceless "Hey! No fair!" look. Oh, Jayne. You're such a naughty tease. If Simon had pigtails, Jayne would be pulling on them. Inara tells Jayne, "Oh, do I ever! Funny and sexy. You have no idea. And you never will." Everybody laughs. Inara explains that she doesn't discuss her clients. I suppose that would be bad for business if everybody knew that the mayor of Backwater liked to wear rubber pants while Inara poured cans of baked beans on his chest. Jayne pushes Inara, but she refuses.
Zoe says to Simon that Kaylee might need some help after all. Simon turns around to see that Kaylee has put together an impromptu cake for Simon with regular-sized candles. Everybody claps and wishes Simon a happy birthday. Simon is shocked, and wants to know how they found out. He turns to River for an explanation. River says, "'Day' is a vestigial mode of time measurement based on solar cycles. It's not applicable. I didn't get you anything." I knew I should have given that episode where River didn't have any lines a better grade. Mal explains that a new warrant for Simon's arrest showed up on the "Cortex." For some reason, it had Simon's birth date on it. Kaylee explains that she had to kind of improvise with the cake. They didn't have the right ingredients, so it's mostly protein. In fact, it's essentially the same goo that they had for dinner. Mmmm protein cakes. Simon tells them all that he's "deeply moved." Mal slaps Jayne's arm away as he tries to sneak a fingerful of frosting. Jayne urges Simon to blow out the candles so that Jayne can give him his birthday spanking. Sorry! Actually, if Jayne's behavior is any indication, I think he wants Simon to give him the -- you know what? I'm just going to shut up now.
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.