However, their refuge is no longer as secure as it once was. They discover a hole in the wall created by thieves attempting to break into an adjoining building. Fearful that their hiding place might be discovered, Anne's father fills the hole with bricks and covers it up. They also find a note left behind by thieves threatening to return at night and report the Franks.
In response, Anne's father removes all books and furniture that might reveal their presence and redistributes them among other rooms. While the family works to minimize signs of their presence in the upper rooms of the house, they become increasingly cautious.