[William falls quiet for a long moment, pensive, not trying to be cold in the face of her anger just-- thinking.]

You chose not to kill him, [he says, finally.] I don't think it's sensible or virtuous to deny that fucking much. You chose that. You thought it'd be better than whatever I was going to do to him, whatever the monsters might do. And you didn't know any better because this ship and its senior inhabitants are all snotty, judgy, mystery-hoarding cunts.

[A beat.] Mind-control is bollocks, [he remembers to agree, nodding.]