Get Smart - 4x14 - One Nation Invisible

Max is assigned to protect Dr. Canyon, the inventor of an invisibility spray. Because Dr. Canyon has sprayed herself with said invisibility spray, Max has no idea she is a beautiful woman. This becomes a problem when Max has to protect Dr. Canyon at his apartment in the middle of the night. Returning home from assignment, 99 arrives back at the apartment just as Dr. Canyon's invisibility spray is wearing off. The title is a parody of the Pledge of Allegiance of the United States, "one nation, indivisible".