as a saboteur, blowing up trains. Matas's father-in-law was only twelve when Denmark had been invaded, and he did not talk about that period very much. However, Matas questioned him about what had occurred, and she learned enough from him about wartime events to be able to craft what she considered to be a good story. During that period, Matas and her family were living in Montreal, and somebody gave her husband the book,Rescue in Denmark, an account of how most of the Jews in Denmark escaped being transported to the death camps. After reading that book, Matas made the rescue the key event in her story, and she transformed the twelve-year-old boy who was in the resistance into a twelve-year-old girl. Lisa, published in the United States as Lisa's War, was followed by Jesper, published in the United States as Code Name Kris. The second book, which uses some of the characters from Lisa, was actually the story about the Danish resistance that had originally intrigued Matas when she had spoken with her father-in-law.

In 1993 Matas published two additional historical fiction titles, each dealing with a nation's attempt to destroy its Jewish population. Sworn Enemies, set in the early nineteenth century, dealt with a historical event unfamiliar to most of the Western world: the attempt by Czar Nicholas I to assimilate and Christianize Polish Jews who had become "Russian" through conquest. The other title, Daniel's Story, presented the Holocaust of World War II through the eyes of a German Jewish boy.

In her autobiographical piece in Something about the Author, Matas explains the origins of Daniel's Story. Matas was just finishing Sworn Enemies when her agent, Amy Berkower, called to ask if she would be interested in writing a book for the United States Holocaust Memorial Museum, which was opening in Washington, D.C. Apparently the museum had approached Beverly Horowitz, who was editing Sworn Enemies for Bantam Doubleday Dell, and asked her to recommend an author, and she recommended Matas.

Describing Daniel's Story as "the most difficult project of my writing career," Matas went on in her essay in Something about the Author to describe how she wrote the book. Her first challenge was time. Matas had received the call from Berkower in March of 1992, and the planned opening of the Holocaust Memorial Museum was the spring of 1993. If the book was to be in print in time for the opening, Matas would need to finish the manuscript in just three months, and she had already committed herself to a long speaking tour in April. Matas assumed that she would be provided with all kinds of material with which to work. Instead, she was only given a set of restrictive directions governing the book's parameters. Because the museum was going to contain an exhibit called "Daniel's Story," the book was supposed to compliment the exhibit. The idea was that children who went through "Daniel's Story" could then go to the bookstore where they would be able to purchase a book and read about what the Holocaust might have been like for a real boy. The character is to be an "everybody," with an individual story. Matas's protagonist must bear the name Daniel, and he must live in Germany. He is to be sent to the Lodz Ghetto, to Auschwitz, and finally to Buchenwald. And he must not die. Remaining within those constraints, Matas could be free to write what she wishes.

The short period available for writing Daniel's Story meant that Matas had to abandon her usual way of doing her research. Unable to organize interviews, Matas researched via history books and videos. Among the source materials she used were memoirs and diaries, many of them by people who had not survived the war. Matas found these personal accounts very moving and said that she cried every day. The tight time line also changed Matas's writing habits. Her normal pattern of researching first, thinking, and finally writing became blended. With Daniel's Story, she began to write while she was still researching, and read at night while writing during the day.

Since penning Daniel's Story, Matas has revisited this historical period in a number of other books. After the War and The Garden both feature Ruth Mendenberg, a concentration camp survivor, who returns to her home village in Poland to discover that she has neither a home nor apparently any surviving family members. In the first book, Ruth travels with a group of children across Europe in order that they might illegally enter Palestine. In the sequel, The Garden, Ruth is living on a kibbutz (a communal settlement) in Palestine when the United Nations partitions the country into two, one for the Arabs and another for the Jews. The experiences of other Jewish adolescents in war-torn Europe are also central to Greater Than Angels and In My Enemy's House. Both books show how some Jews escaped Nazi persecution by hiding or being hidden.

Anti-Semitism is integral to The War Within, set in the Confederate South during the American Civil War, and Rebecca, which uses 1912 Winnipeg as its locale.

While Matas has written almost a dozen books of historical fiction, she has not entirely abandoned the genre of science fiction. She has produced a pair of linked SF titles, Cloning Miranda and The Second Clone, and with her coauthor, Perry Nodelman, Matas has written the "Mind" series of fantasy titles. Additionally, she also writes mainstream young adult fiction such as The Primrose Path and Telling.

Critical recognition has been bestowed on virtually every one of Matas's young adult books. Lisa, her very first work of historical fiction, was the inaugural winner of the Geoffrey Bilson Award for Historical Fiction, Canada's premier prize in this genre. Among its many accolades, Daniel's Story, was nominated for the Governor General's Literary Award in Children's Literature and received Ontario's and Manitoba's provincial readers' choice awards.