March, march, march, in to the jungle, across a stream. Rousseau sees a scrap of fabric tied to a tree. "De territoire fonce," she says, which Jack translates to "the dark territory," although I think it should be "foncé," but I could be wrong. "The Black Rock is not far," she says. "This is where it all began. Where my team got infected. Where Martin lost his arm. We must move quickly." Good thing you brought Hurley along, then. Not to mention Arse, who says, "You know what? I'm going back." Jack says he thought Arse wanted to help, which Arse says was before "Martin lost his frickin' arm!" And he takes off, and his only advice re: the dynamite is to be very careful with it. Jack glares at Arse's retreating arse. Oh, Jack. Arse always does this. When will you ever learn?
Back on the raft, Mercutio and Jin's Han Solo/Chewbacca-type relationship is given a direct shout-out with Mercutio yelling, "No, no, no! This one goes there, that one goes there!" Heh. Jin actually says, "Okay, okay, okay," in English, no less. Then Sawyer strolls up, with his shirt off again, like make up your mind, and he's carrying the bamboo or whatever with him. "Hey, chief!" he yells, dropping it on the sand. "Cut and measured to length. Perfect mast." Thanks for finally pitching in, Sawyer. Have a friggin' cookie.
In the jungle, it's started raining. So they may be marching to their deaths, but at least they're cold and wet and miserable. Then they hear it: some kind of crazed hooting somewhere through the bushes, and everybody stops, paralyzed. I'm thinking, "Sweet, we're finally going to get some action!" But turns out it's just Arse, running screaming through the jungle. He passes them, yelling, "Run! Run!" Commercials.
Arse goes screaming by, and Rousseau, Kate, and Jack take off after him. Hurley goes to follow, but Locke tells him to hold on for a second. And we hear the metallic roar of Lostzilla. Hurley's like, "Is it okay if we get out of here now so as to continue living?" Jack and the women fortunately find that grove of trees that everyone always takes refuge in. Hurley says, "Dude, we gotta book," but Locke holds him, and the sounds of Lostzilla recede. You know, if we don't see this whatever it is in the season finale, I'm going to be some pissed.
"We're safe now," says Rousseau. Kate wants to know what that thing was. "Security system," says Rousseau. "'Security system.' What does that mean?" says Jack, and Rousseau explains that a security system protects something, like, I don't think he was asking for the definition of security system, here. "Protect what?" asks Kate, and Rousseau says, "The island," looks at Kate like she's an idiot, and strolls off. Kate and Jack exchange looks. I love how no one questions Rousseau very much. She gives these cryptic answers, and everyone just gives up. They're called follow-up questions, you nimwits.