Then the beeping starts. The biker gang pirates are sailing down the hatch-hole? Up in the air duct, Kate hears it too. Desmond tells Locke to get up, and they go into the room with all the ancient (well, '80s, anyway) machinery. Pointing to the computer, Desmond asks Locke if he knows how to use it. Locke says he hasn't seen one of those in twenty years. Locke, next time someone asks if you know how to use an old computer? You say yes! Actually, that's exactly what then happens, with Desmond's rifle used as an exclamation mark. There's a timer on the wall behind the computer, reading 00238, with the first three digits in white numbers on black, and the last two black numbers on white. Looks like minutes and seconds. Desmond tells Locke to enter exactly what he's told and nothing else. Then Desmond starts listing the numbers: "Four, eight, fifteen..." Desmond's momentarily distracted, asking if Locke heard that (I didn't hear it). Locke didn't. Desmond finishes telling Locke the sequence (how freaked out would Desmond have been if Hurley were there and he guessed the rest of the numbers?), then orders Locke to hit the EXECUTE button. Locke hesitates, presumably worried about what might happen when he does, but then hits it. The beeping stops, and the timer resets to 10800.
Then we hear, in the distance, "Kate! Locke!" Desmond whirls around, points the gun back at Locke. "What's that?" "That would be Jack," says Locke, looking more curious than anything about how this is all going to play out. Of course, Locke's odds of survival just went up. I don't mean because Jack is there to rescue him, just that...well, if you had a rifle, who would be your first choice to shoot? Jack or Locke? That's what I'm talking about.
Back from commercial, Desmond hauls Locke over to his bazooka telescope tube, where he watches Jack make his way down the hall. He asks Locke who it is. "He's our doctor," says Locke. Desmond asks what he's doing here. "To be honest with you, I'm surprised to see him." How about you try answering the crazy rifle-toting man's question instead of making a wiseass remark? Desmond keeps watching him. "Your doctor has a gun, brothah." He hauls Locke over the record player, and you're kind of half-expecting him to say, "Have you ever actually really listened to Jethro Tull? Like really listened to it?" Instead, he drops the needle on a record, and "Make Your Own Kind of Music" comes back on.
Up in the Air Duct of Skulking Pendulous Cleavage, Kate stops creeping along just long enough to make her patented My God, Is That Mama Cass? face.