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 most durable thing in writing is style, and style is the most valuable investment a writer can make with his time. It pays off slowly, your agent will sneer at it, your publisher will misunderstand it, and it will take people you have never heard of to convince them by slow degrees that the writer who puts his individual mark on the way he writes will always pay off.”
—Raymond Chandler (1888–1959)