The Doctor: Let me negotiate peace. You can't commit mass murder... Kate: Then why did you leave the gas with us? The Doctor: The boxes are safeguards for both species.
Osgood: Never really met Clara. Pretty strong, yeah? The Doctor: She was amazing. Osgood: No, not was... is. It's not from the Zygon. It's from Clara. The Doctor: How? Osgood: She's not dead. She's in a pod somewhere.