D-Day, June 6, 1944: the most expansive military endeavor in history. No less than world cooperation would bring down Hitler and the Axis powers. And so people - and kids - across the globe lent their part. From the young US soldiers in the boats to spies in the French countryside, the coordination of thousands came together.

Alan Gratz, author of the New York Times best-selling Refugee, explores the necessity of teamwork and heroism in dismantling tyranny in this epic, yet personal, look at D-Day in time for the 75th anniversary of the operation.