Kara fauxallas in to Adama that the O2 is fine in the lounge, and she and Adama decide that it was Lee: "Maybe he's giving us an opening. If I can get someone inside, get a clear idea of what we're dealing with..." Knowing how Kara's plans generally consist of two simple steps -- Jump In and Don't Die -- Adama calls her "Kara" and reminds her that she's only on a recon mission. Her face gets hard, because obviously she's going to risk herself: it's Lee. Not up for debate. Adama: "Get someone to volunteer. Then you assess the situation. And then get the hell out of there. Do you understand?" She gives a fake assent and then, conveniently, the maintenance guy shows up. She takes his hat, puts it on, and looks hot as hell some more. "Captain," says the ever-increasingly worried Burrel, "What are you doing?" And you already know her answer: "Volunteering."
The goons admit Starbuck, now wearing overalls to go with her lovely hat. Sesha orders them to close the door and search her, and Starbuck reminds them that the O2 clock is ticking. Frisked and cleared, and her toolbox checked, she makes her way around the room to the back, covered by Vinson. Who notices Ellen recognizing Starbuck. This is the well-known dramatic rule of Chekov that goes, "When there's an Ellen in the teaser, she's sending us all to hell by the third act." I wouldn't have it any other way. Vinson tells them to check the box again, and at least Ellen has the class to look sheepish about how she just got them all totally killed.
Starbuck sighs, closes her eyes for a second, and pulls two guns out of the toolbox's false lid. (Note to hostage takers: Get references for your goons. You'll thank me.) Everything goes nuts as she and the perps start firing and the Marines bust in, immediately losing two-thirds of their number.