Kara Thrace: Ok, what the hell's going on? I'm off the ship for a few hours and...
Sam Anders: A few hours? Kara you were gone for over two months.
And the critical scene:
Lee Adama: Dad, what if Zak had come back to us in that viper? ... If my brother had climbed out of that cockpit... would it matter if he were a Cylon? If he always had been? When all's said and done, would that change how we really feel about him?
Bill Adama: (silence)
Battlestar Galactica - 4x01