Every night, under a quarter moon, the runners come.

The Nassau Passage takes the Civil War to sea in a pulse-pounding alternate history of the Confederate supply network — the British merchants, French arms dealers, Nassau middlemen, and reckless captains whose shallow-draft steamers slipped through the Union cordon and delivered the weapons that kept the Southern war effort alive.

Commander Josiah Bell of the USS Iroquois knows he is losing this fight. He can count the rifles arriving in Wilmington. He can smell the coal smoke of runners passing in the dark. What he cannot do — what no officer in the blockading squadron can do — is stop the French convoy when it arrives under naval escort, laden with Chassepots and artillery, carrying the imprimatur of Napoleon III himself.

This is the overlooked war inside the Civil War — the economic war, the naval war, the war fought with ledger books and manifests and Lloyd's of London insurance policies. The Nassau Passage is nautical alternate history at its finest: meticulous, propulsive, and built on the astonishing true history of how one of the most ambitious supply operations in military history actually worked.