In Anne Frank:The Diary of a Young Girl, the British forces are advancing and Germany feels that Holland may be under threat from a British or Allied Forces invasion, much to the delight of the occupants of "The Secret Annex."
The difficulties lie however in the fact that Anne Frank and her family and friends, like so many other Jewish families, are in hiding and if Germany do anything drastic, they will be forced to come out of hiding, disguising themselves as best they can and mingling with the Dutch people which is highly dangerous.
Anne informs her diary, which she has called "Kitty," that the Germans, according to the newspapers, have threatened to flood much of Holland which is based on a series of canals so is a very real threat. Maps have even been issued showing the potential areas around Amsterdam that may become flooded in this event. The people in the Annex make jokes about any such possibility, evidently to hide their fear which then leads them to wonder what they can do if Germany even evacuates Holland. They feel it would be better to stay in the Annex, encourage others to join them and accumulate what they can because, leaving Holland and arriving in Germany, they would all likely die.