Final answer:
The specific answer to what Esther was doing when the Gestapo caught her is not provided in the reference material. However, the references discuss various forms of resistance during the Holocaust, including the Warsaw ghetto uprising and the actions of individuals who worked to save Jewish lives.
Step-by-step explanation:
The student has asked what Esther was doing when the Gestapo caught her at the barn on the way to Warsaw in the book Resistance. The correct answer to this question is not explicitly provided in the reference material since this seems to be a specific question from a book, and the information given does not include details about a character named Esther or her actions in a barn.
However, the references provided do discuss the various forms of resistance that took place during the Holocaust, including the heroic but ultimately unsuccessful Warsaw ghetto uprising, acts of cultural and spiritual resistance by Jewish communities, underground resistance movements in ghettos, and the actions of people like Irena Sendler and Oskar Schindler, who worked to save Jewish lives.