A unique historical thriller takes on the true mysteries of Lincoln's assassination "with verve, humor and impressive scholarship" (Time). In 1868, Pinkerton Detective Nicholas Cosgrove is tasked with tracking down John Wilkes Booth, a man who should be three years in his grave. Booth, President Lincoln's assassin, was also a skilled actor and master of disguise, and Secretary of War Edwin Stanton suspects he may still be at large. But Cosgrove unearths more than just the corpse of a man who is decidedly not Booth. The conspiracy to assassinate Lincoln was much larger, and far more dangerous than anyone suspects.   Now, more than a century later, Cosgrove's report on his harrowing investigation has fallen into the hands of private eye Michael Croft. Charged with verifying Cosgrove's hair-raising tale--as well as its explosive implications--Croft presents the manuscript here with his own annotations.   With meticulous research into official records as well as the forgotten memoirs of eyewitnesses, former CIA agent G. J. A. O'Toole has crafted a highly original novel--both a gripping historical thriller and a shockingly plausible solution to some of the most enthralling mysteries surrounding Lincoln's assassination.   "A humdinger of a mystery . . . transports us to a landscape at once familiar and as exotic as a sinister, murderous oz." --The Washington Star   "It has everything--mystery, adventure, history, and a delightful unsuspected ending. . . . The unique tale of an American Sherlock Holmes." --Seattle Times Magazine   "With impressive scholarship and sharp wit, O'Toole lays bare for the non-specialist the real and persistent mysteries that still surround the trial of the Lincoln assassins. Altogether, highly entertaining and highly informative." --Historical Novel Society