March 1945: After a career of commanding destroyers in the Pacific theater of WWII, Captain Wolfe Bowen is based in Washington, DC, working for the chief of naval operations. Bowen receives an urgent call from the commander of the naval shipyard in Portsmouth, New Hampshire: a German U-boat has been captured and brought to port. But what grabs Bowen's attention is the presence of two Japanese civilians on board, along with the massive size of the U-boat itself. What these civilians know about the cargo of the U-boat, as well as its destination, begins a race against time that will change the course of history.

When President Franklin Delano Roosevelt dies, Harry Truman ascends to office with no prior knowledge of the Manhattan Project. Bowen is assigned a dangerous mission: discover whether Japan has the technology to produce an atomic weapon, and find out how close the desperate enemy is to deploying it. Working with a small team, Bowen must report back to President Truman with the information that will transform the war—and the world.

Brilliantly imagined and deeply informed by P. T. Deutermann's long history as a navy captain, as well as his family's service in the Pacific theater, The Second Sun is a compelling novel timed for the 80th anniversary of the end of World War II.