It is 1801 and President Thomas Jefferson has assembled a deep-water navy to fight the growing threat of piracy, as American civilians are regularly kidnapped by Islamist brigands and held for ransom, enslaved, or killed, all at their captors' whim. The Berber States of North Africa, especially Tripoli, claimed their faith gave them the right to pillage anyone who did not submit to their religion.

Bliven Putnam, great-nephew of Revolutionary War hero Israel Putnam, is bound for the Mediterranean and a desperate battle with the pirate ship Tripoli. He later returns under legendary Commodore Edward Preble on the Constitution, and marches across the Libyan desert with General Eaton to assault Derna, discovering the lessons he learns about war, and life, are not what he expected.