The Doctor and Rigg in “Nightmare of Eden”

The vraxoin must be found.

Yes, bad stuff.

Bad stuff? It's the worst! I've seen whole planets ravaged by it while the merchants make fortunes.

Your people knew it would be on board, did they?

My people?

Well, you're an agent, aren't you?

No! I'm the Doctor; I keep telling you that.

Yes, but who do you work for?

W... Work for? I don't work for anybody. I'm just having fun.

Well, everybody works for somebody...