EPZO: Whatever happened here is in the past. What does it matter to you?

DOCTOR: This was a living, breathing planet once. With an ecosystem, organic life, and a population. There was a catastrophic event here. And as hard as it is for you to understand, you are not the only lifeform in this universe. Some of us feel a duty to others who might be in trouble. So fix your wound, take one of your heroic naps, and we'll wake you when we leave – if you're lucky.