Six years before he took command of the Starship Excalibur, a young Starfleet officer named Mackenzie Calhoun served as first officer aboard the U.S.S. Grissom. Then diaster struck, and Calhoun took the blame. A court-martial led to his own angry resignation from Starfleet... or so it appeared. At long last Captain Calhoun reveals the true story behind the greatest tragedy of his life.