Twelve-year-old Lidia is outside her grandfather's house when planes fly overhead, bearing the Nazi cross on each wing. Before the bombs hit the ground, Lidia realizes her life is about to change forever. Poland has fallen under German occupation, and her father makes the brave decision to join the Polish army to fight against the Nazis. Lidia wants to follow him into war, but she's far too young, and she's needed by her mother and brother.

After her family returns to Warsaw, where life has changed irrevocably, Lidia continues to play the piano, finding comfort in Chopin, Bach, and Beethoven. But she also wants to aid the Jewish people held captive in the Warsaw Ghetto. With the help of a friend, Lidia begins to smuggle wheat and food into the ghetto. Still, she feels like she could be doing so much more. She wants to fight. After her brother joins the resistance, Lidia wants only to follow in his footsteps. Soon, she begins to work as a courier, smuggling weapons and messages for the resistance throughout the city.

When the Warsaw city uprising begins—one year after the more well-known Warsaw Ghetto uprising by Polish Jews—with gunfire and bombs echoing throughout the streets, Lidia joins the Polish nationalists' fight, too, and she and her peers fight with everything they've got. Life will continue to surprise Lidia, as she and the resistance fighters do their best to defeat the German soldiers. No matter the consequences, they're willing to defend their freedom and their homes from the Nazi invaders—even with their lives.

Drawing on the extraordinary real-life story of Polish teenager Lidia Zakrzewski, bestselling author Jennifer A. Nielsen presents an inspiring and dramatic account of the Polish resistance fighters who struggled to force out their Nazi occupiers and reclaim their nation's freedom from tyranny.