When Anne and the family first go into hiding what is Anne afraid of the most?
Anne is afraid that their hiding place will be discovered. They are above a business, and the only thing between them and the business is a hidden door behind a bookcase. They have to be very quiet during the day so no one will hear them.
The fear is a realistic one. One time the tenants of the Secret Annex were not warned that a carpenter was coming to refill the fire extinguishers in the offices below. They were not being quiet at the time, because they were not expecting anyone, and then they heard hammering from below. Anne says the carpenter put his tools right by their bookcase, and they all “turned white with fear.”
I was so scared I nearly fainted at the thought of this total stranger managing to discover our wonderful hiding place. Just when I thought my days were numbered, we heard Mr. Kleiman's voice saying, "Open up, it's me." (Tuesday, October 20, 1942)
Apparently the bookcase door lock got stuck and no one was able to warn them. This incident is an example of how the family was always living in fear that someone would discover them. They knew that if they were found out they would be sent to a concentration camp and likely death would result. The same fate would likely befall anyone who helped them.