Chandler sets out to prove that the mysterious death in 1809 of explorer Meriwether Lewis was a murder and that the plot was masterminded by an ally of former president Thomas Jefferson and sanctioned by Jefferson himself. The death of Lewis -- explorer with William Clark, protÃ‰gÃ‰ of Jefferson, and governor of the newly acquired Louisiana Territory -- caused surprisingly little scandal or inquiry, despite its strange circumstances. Having been summoned to Washington to explain his trading expenses, Lewis died of gunshot wounds in an isolated frontier inn along his curiously inconvenient overland route. A hurried verdict of suicide came primarily from John Neelly, the local Indian Bureau liaison, and Jefferson later supported this, even insinuating drug or alcohol addiction. Local rumor said Lewis was murdered, either by Indians or frontier bandits, and later historians have suspected Neelly and Lewis's servant. Chandler's conspiracy theory fingers the disreputable Revolutionary War general James Wilkinson, later in his career a paid Spanish agent and a conspirator in Aaron Burr's planned invasion of Mexico. Wilkinson counted Jefferson as a longtime ally, particularly after double-crossing Burr and testifying at the infamous treason trial, but in 1809 a New Orleans army base scandal threatened to ruin him and possibly embarrass Jefferson. Chandler suggests that since Lewis could have damaged Wilkinson in Washington, Wilkinson sent his agent Neelly to intercept and murder Lewis. Pulitzer Prize-winner Chandler (The Binghams of Louisville, 1988) lays out the multifarious agendas of France, Spain, and the United States -- and the schemes of their agents and adventurers -- in his effort to uncover links between Wilkinson and the prime suspects in Lewis's death. Despite Chandler's bias against Jefferson, his role in a possible cover-up, much less a conspiracy, remains questionable. Chandler fits persuasive, albeit circumstantial, evidence into the puzzle of Lewis's death, situating it in the country's turbulent early era, but ultimately does not fill all the gaps and unknowns.