Anne Frank

From the text:

Because so many houses are being searched for hidden bicycles, Mr. Kugler thought it would be better to have a bookcase built in front of the entrance to our hiding place. It swings out on its hinges and opens like a door. Mr. Voskuijl did the carpentry work. (Mr. Voskuijl has been told that the seven of us are in hiding, and he's been most helpful.)