Felix slept, on New Caprica, blissfully asleep, while Sweet Eight took his list and handed it to her sister. Eights know more of our scripture than we do, but they're very literal. "Kill everyone on this list."
He knows she's lying, now; it itches in a place he can't scratch, but he remembers. He saved Jenkins, and Pembroke, put their names on the list and watched them walking in the sunlight again. Saw Heather Redmond and her baby, playing together. Those weren't dreams, or lies. He was doing the right thing. Eight shakes her head at him, sadly.
"I'm a woman, and a Cylon: I didn't seduce you. Hope seduced you. And the more you ate of it, the less you saw. You ate yourself blind." Felix calls out, lost to pain, worlds aching beyond his grasp, leg burning, asking why she didn't just kill them all, when she knew that they were lost. "I'm not a monster, I didn't want to do what I did. I did it when the probabilities dictated it." Same moment, different world, fifteen months and lifetimes apart. "You kill when you're in a war. You kill when you have to. You kill the ones your enemy values. It's basic. You should know that." He does know that; he did know that.
"I'd tell you that they'd run off," she reminds him, "Or they were at the infirmary. Some of them I'd say I saw them eating with their families. Didn't you see them? Oh, I'm sure you'll see them tomorrow." Some nights it itched so bad he'd double up his dose, singing at the top of his lungs in some forgotten corner of the world; when they put him on his knees in the launch tube he nearly touched it. It was too big. But Gaius knew, didn't he? When they had him in the brig, right before his trial, and sent lovesick Felix in to gain his trust, that's exactly what Gaius said.
"What did you tell them? That you stayed behind till the grisly end on New Caprica, so that you could what? So you could feed information to the Resistance? Who do you think allowed you to do that? You think I'm blind? You see, I literally had a gun pointed to my head. But nobody forced you to play both sides. There's not much difference between my brain and yours, Felix. We can choose to not make the connection! You can see someone kill in front of you, twice, and still hang on to your ignorance. Instead of calling it a flaw, you call it hope, or faith. Love. So I'm asking you, Mr. Gaeta: who is the real traitor in this room?" And Felix swore he wasn't. "No, of course! Because there are far worse things than being a traitor, aren't there? If your friends only knew the truth. But don't worry, I know about your little secret."