"Number the Stars" by Lois Lowry is a popular historical novel for adolescent readers about the Nazi occupation of Copenhagen, Denmark during World War II and the efforts of Danish resisters who successfully rescued 98% of that nation's Jewish population. While this 1998 book is considered to be a fictional account, most of the events in the story are historically accurate and based on authentic sources, people, and events. As historical fiction becomes increasingly popular regarding the integration of social studies and language arts, it is important for teachers to assume the responsibility of leading students to information that is historically accurate and valid. The purpose of this article is to demonstrate how teachers and students can use nonfiction resources to not only validate the texts that they are reading, but also develop critical thought processes and strengthen comprehension. (Contains 15 notes.)