Scandal, Season 2

Abby:
Spies listen to the radio?

Huck:
Anything high-tech you can break into. With a radio, you can't trace where it comes from, you can't trace who's listening. The radio is how we talk to each other, how all spies talk to each other. All around the world. You listen every day and every day there's no message. Years go by and decades and there's no message and then one day you listen and the code word comes.

Abby:
And then what happens?

Huck:
It's time to come home.