Why does Peter Neilson still stop at Annemarie's house in Number the Stars?
Peter Neilson had been engaged to Annemarie's older sister Lise. Even though Lise is dead, Peter is still very close to the family. At first, his continued visits to the Johansen household were most likely motivated by friendship and familiarity. As the Germans began taking over more and more of Europe, however, his visits took on an additional purpose as well, as he and the Johansen parents became increasingly involved in the resistance.
Lise Johansen, "tall and beautiful", had died in an accident two weeks before her wedding to Peter. "Redheaded Peter" had not married anyone in the years since Lise's death, but he still stopped by the Johansen house often. Annemarie's parents loved Peter..."they said he was like a son". Peter had once been like "a fun-loving older brother" to Annemarie and the youngest Johansen daughter, Kirsti, but as the political climate deteriorated in Denmark, his visits, although still warm and friendly, had become more serious. Now when he stopped by the apartment, "he was usually in a hurry...and he never ligered anymore...he seemed much older and very tired, defeated". Peter was working in the resistance, collaborating with concerned Danish citizens to protect the Jewish population amongst them from the German threat. Together with Mr. and Mrs. Johansen, their participation in the underground results in an attempt to help the Rosens escape deportation and annihilation at the hands of the Nazis (Chapters 3-4).
Peter was engaged to Annemarie's older sister, Lise, who passed away. The Johansens love Peter because he was like a son to them, even though he and Lise were never able to get married before she died. The younger Johansen girls love Peter and look up to him as a brotherly figure. Peter is a member of the Resistance and stops by to deliver illegal newspapers to Annemarie's parents. He also plays a role in moving Ellen and her family to safety as they escape German occupied Denmark.