Anne Frank and her family spend two years in The Annex as revealed in Anne Frank: The Diary of a Young Girl and their access to the outside world is very limited. They crave information and confirmation that the Germans will be defeated so any news of the underground activities is very encouraging to them, especially after they hear so many heart-rending stories about Jews being captured and mistreated.
I feel wicked sleeping in a warm bed, while somewhere out there my dearest friends are dropping
from exhaustion or being knocked to the ground. Thursday November 19 1942.
It has become commonplace for people to go underground or into hiding. As Anne says, it's like the "pipe and slippers"(Friday January 28 1944) routine when a father would arrive home at the end of a day's work. Identity documents, ration cards such as the ones the Franks receive and hiding places or jobs for underground Christians are the work of the underground as families, both Jew and Christian, try to fend off the Nazi regime.