Mirage is a 1965 thriller directed by Edward Dmytryk from a screenplay by Peter Stone, based on the novel Fallen Angel, written by Howard Fast under the pseudonym Walter Ericson; the novel is not credited by title onscreen. The film stars Gregory Peck, Diane Baker, Walter Matthau, and Kevin McCarthy, and was released by Universal Pictures. Wikipedia
David Stillwell: What about your secretary? Don't you want to leave a note or something?
Ted Caselle: I will tell the truth. I don't have a secretary and there is no partner. As a matter of fact, you are my first case.
David Stillwell: (sarcastically) Terrific.