He pushes her under the water or into fellatio or something, and then begins to drown, all alone. "I can't stay afloat much longer!" Adama demands "details" about the Cylons and threatens to let him drown (which he pronounces with a very East-L.A. /d/ at the end, like the past tense) "alone, in the dark." Adama turns off the light; the water goes black. Gaius's face, both in the lab and in the water, contorts with fear, and when he screams, he screams in two voices at once.
Lee spins his wedding ring on the bar at Joe's, stabbing his finger down as it slows. Chief approaches, and signals for a drink. He's really sad. It's really sad. "Why is it so frackin' hard?" he asks, but Lee has no answer. "Why can't we just get back to normal?" He laughs, wondering what the hell "normal" means anyway. Remembers when she forgave him, and they got married, and Baby Nick was born, and it was dirty but they were happy. Normal. Apollo sips his drink, Chief stares into space, into the gap, imagining conversation after conversation. Lee makes a decision and his lips go firm. "Chief, you can tell me if I'm out of line here, but, um...do you ever think about Sharon?" Chief stares at his glass, blurts, "No," then chugs. Lee refills his drink and presses: "Come on. You never wonder...what if?" Chief picks up the glass and looks him right in the eye: "No." He chugs the drink again, and bashes the glass down on the bar, and wanders away, leaving a gap, a tiny little space for Lee to fill with anything. With guilt. Turns out he's alone in that club after all, he decides, although he's wrong. It's a parallel we didn't have time to make before, but it's valid. Lee stares at his ring and wonders how we get back to normal -- how everybody gets out alive.
"Look, don't leave me! Don't leave me. I know I'm flawed. I never claimed to be... Yeah, mistakes, mistakes were made. Terrible mistakes. Were they mine? Am I solely to blame? I was a player, that's all. I was a player. I was struggling, trying to find my place in God's plan." It's Gaius talking. Who'd you think? Can you name a character who isn't screaming this throughout the entire episode? Roslin begins to cry.
"I never intended for certain things to happen! Doesn't that matter?" (Still Gaius.) Adama brings up his trip with the Cylons to the Temple of Five, asks about the Eye. "What did it tell them? What did it tell them about Earth?" Gaius can't find the words to explain how for the Cult of Just The Two Of Us, Earth was secondary to stuff that's none of Bill's business; the light comes back. "What were you looking for, Doctor? What were you looking for?" A thousand things he doesn't have words for, so he'll substitute Three's. The black ocean becomes a resurrection pod, but there's just water in it. He looks very clean, and very beautiful. Hands caress him, all around, and many voices sing, wordlessly. "Their faces," Gaius says, "But they wouldn't show them to me." Roslin asks whose faces; "The Five. The Final Five." Roslin wows. The camera pulls back to reveal the owners of the hands: the burned, dead children of Aerelon, of Caprica and Geminon, of Picon and Sagittaron, Tauron and Virgon. All his victims, his orphaned and his irradiated and his burnt and starving, the legacy, the billion children of Gaius Baltar. God looks nothing like that! Everybody knows that.