DOCTOR: I've seen worlds destroyed, civilisations choked in their cradles, whole races fleeing in terror. I've seen centuries of art, of science, wiped out in an instant. I just saw a beautiful rainforest burn along with every creature in it. I didn't even know the planet's name! If you're prepared to accept that much collateral damage to the rest of the universe, then what exactly are you fighting for? I'll protect those with no choice in the matter, no voice.