In recent years I’ve endeavored to give young readers real-life protagonists their own age. I want my readers to ask themselves, “What would I have done?” I believe that teens experience sharper pangs of injustice than adults, and a greater determination to do something about it. Some, such as Claudette Colvin, have acted with amazing courage. As Dr. King said of the civil rights movement, “The blanket of fear was lifted by Negro youth.”

The Boys Who Challenged Hitler is the story of a group of Danish middle-school students who were passionately ashamed of their government for bowing to the German forces that invaded their country on April 9, 1940. Rather than kneel to the enemy, these schoolboys vowed to “clean the mud off the Danish flag.” They formed a sabotage cell called the Churchill Club and taught themselves, on the job, how to trouble the German army. After a six-month spree during which their activities escalated from vandalism to the theft of high-powered weapons to the grenade bombing of German vehicles, they were captured. Word of their arrest raced through the country. There was great concern that the boys would be executed. Their courage shamed and inspired Danish citizenry to stand up against their occupiers.

After the arrest, the great Danish poet and playwright Kaj Munk expressed the national mood in a letter to the parents of ringleader Knud Pedersen and his brother Jens: “Of course what [the boys] have done is wrong; but it is not nearly so wrong as when the government gave the country away to the invading enemy…I pray to God to give them cheerfulness, endurance, and constancy in the good cause.”

I met Knud Pedersen in Copenhagen in 2012. He was eighty-six. In the previous seventy years there had been film nibbles and book offers to tell the story of the Churchill Club, but nothing had panned out. Knud knew that my interest probably represented his last chance to tell the story right, and he took full advantage of it. I interviewed him for a solid week, which led to hundreds of follow-up emails and, ultimately, the book you have honored here.

I think this story is especially important. The Churchill Club boys, some of whom had yet to shave, took on a hopelessly big Goliath. They had no military training and had not been desensitized to violence and killing, as are soldiers in basic training. In shrill voices the boys debated the ethics of taking lives. Was it ever right? When? Who decides?

As Anne Whaling, children’s book buyer at Mrs. Dalloway’s Bookstore in Berkeley, California, has commented, “The book raises lots of thought-provoking questions, as the best books always do: When do you stand up, even fight, for what is right? How would you do it? How far would you go? And, in today’s world, where is the line drawn between political activist, vandal, and terrorist?”

From the January/February 2016 issue of The Horn Book Magazine. For more on the 2015 Boston Globe-Horn Book Awards, click on the tag BGHB15.