John le Carre wrote fiction espionage novels. Espionage novels are novels which focus on a spy's life or spying in general. His most famous work is The Spy That Came In from the Cold.
The definition of a ditz is slang for someone who is silly or who seems to have scattered thinking. An example of ditz is a silly dumb person who just giggles all day. ditz. Slang a person thought of as being flighty, eccentric, silly, etc. ditz.
A Hertz is a unit of frequency defined as a reciprocal second, s-1. For example, AC current cycles polarity 60 times per second, so we could call this 60 Hz = 60 s-1.