As Ackerman discusses in her Author’s Note, she not only researched the historical records of the Holocaust, the Warsaw Zoo, and many noteworthy individuals exhaustively, but she also read the personal writings of Antonina. Antonina’s voice plays a prominent role in the text, and direct quotations from her journals are present throughout. Jan’s writings and interviews are another key source of information for the book, especially as they pertain to his work in the resistance movement and in hiding Guests in the villa.

The author also discusses secret, hidden records compiled by non-Jewish Polish people who worked to help Jews escape from the Ghetto, as well as Jewish residents themselves. These records were hidden in butter churns and other inconspicuous places where they would not be found until after the war. Ackerman’s access to all these writings enables her to tell the story of the multitude of resistance workers who saved the lives of tens of thousands of Jewish Warsaw citizens.

Those familiar with Ackerman’s work will recognize the abundant descriptions she uses when describing the settings of Warsaw, the campus of the zoo, the varieties and even personalities of