Some themes and topics in "Then" by Morris Gleitzman that can help you draw connections to other books in a library are:
* **The impact of war**, particularly on children. The book explores children's responses to traumatic events. 【1】【2】
* **Family**, both chosen and biological, and its complexities. 【3】【4】
* **Survival** in a hostile environment, specifically Nazi-occupied Poland in 1942. 【4】【5】
* **Love and hope** in difficult circumstances. 【4】
* **Friendship** between children from different backgrounds. 【6】【7】
* **The Holocaust** and the experiences of Jewish people during World War II. 【5】【8】
* **Ethical dilemmas** and moral ambiguities in wartime. 【9】
* **Loss** and the search for loved ones. 【10】【11】