The middle-grade novel “Nine, Ten: A September 11 Story’’ (Atheneum) centers on the lives of four middle-school students from diverse backgrounds who pass through the Chicago airport in the days prior to the terrorist attacks on Sept. 11, 2001. Author Nora Raleigh Baskin’s treatment of the attacks comes late in the story and is restrained. Instead, she focuses on the interconnectedness of Americans from disparate backgrounds and the spirit of generosity that was in evidence in the immediate aftermath of the tragedy. Each of the four students becomes more sensitive to the suffering of others. It’s a good lesson for readers of all ages.

JAN GARDNER