A walk-in agent is an individual who voluntarily offers to conduct espionage. Specifically, a "walk-in" is an agent or a mole of a government who literally walks into an embassy or intelligence agency without prior contact or recruitment.
Famous quotes containing the words walk-in and/or agent:
“With four walk-in closets to walk in,
Three bushes, two shrubs, and one tree,
The suburbs are good for the children,
But no place for grown-ups to be.”
—Judith Viorst (b. 1935)
“The agent never receipts his bill, puts his hat on and bows himself out. He stays around forever, not only for as long as you can write anything that anyone will buy, but as long as anyone will buy any portion of any right to anything that you ever did write. He just takes ten per cent of your life.”
—Raymond Chandler (1888–1959)