All three novels revolve around two brothers, Claus and Lucas. They are twins. Perfect reflections of one another. In The Notebook, they are abandoned at their grandmother’s during a brutal war (presumably World War II) in their country (presumably in Europe) and, using a notebook, they practice hardening themselves against outside threats and internal ones as well.
One things about horror is that it can be a bit loud or garish in the way it delivers the message is seeks to convey. Lessing doesn’t do this.
It turns the audience into an eavesdropper, listening to thoughts said aloud when a character is alone.