The late-18th- and early-19th-century U.S. soldier James Wilkinson enjoyed “one of the most extraordinary careers as a secret agent in the history of espionage,” writes Andro Linklater. Code-named Agent 13, Wilkinson provided Spanish authorities in North America with important information about American intentions and capabilities, even while he served as commander in chief of the U.S. Army. As Linklater also points out in this fascinating biography, Wilkinson’s actions were not exactly secret. Many people in the young republic—including its first four presidents—had reason to suspect his loyalties.