The X-Files, Season 1

Deep Throat:
Leave this case alone, Agent Mulder.

Mulder:
What?

Deep Throat:
The military will not tolerate an FBI investigation.

Mulder:
Who are you?

Deep Throat:
I, er, can be of help to you. I've had a certain interest in your work.

Mulder:
How do you know about my work?

Deep Throat:
Well, let's just say that I'm in a position to know quite a lot of things, er, things about our government.

Mulder:
Who are you? Who do you work for?

Deep Throat:
It's unimportant, I came here to give you some valuable advice. You are exposing yourself and Agent Scully to unnecessary risk, I advise you to drop the case.

Mulder:
I can't do that.

Deep Throat:
You have much work to do, Agent Mulder, don't jeopardise the future of your own efforts.