The Cosgrove Report is ""the Private Inquiry of a Pinkerton Detective into the Death of President Lincoln""--a 19th-century manuscript which has been left to the nephew of a present-day millionaire, who in turn has hired private-eye Michael Croft to ascertain the manuscript's authenticity. And though Croft writes a foreword and afterword here, Cosgrove's first-person report is the bulk of this historical flimflam. It's 1868, and Cosgrove has been hired by Secretary of War Stanton to find John Wilkes Booth, who--so says rumor--may really be alive! And Stanton certainly should know about that; according to the theory here, assassination conspirator Stanton allowed Booth to escape following the assassination and kept the eight captured conspirators in separate cells and bound in cotton-lined head bags so that they could not breathe a word of Stanton's association with Booth and with General Lafayette C, Baker, the U.S. Secret Service head who employed Booth as a double agent against the South. So off goes Cosgrove on Booth's trail: he first finds that Booth's grave is empty, then discovers that it was indeed a pseudo-Booth who was shot and killed. And he pursues the key clue of Booth's Other Boot--the one that wasn't cut off by Dr. Samuel Mudd when attending to Booth's broken leg. Eventually Cosgrove fastens on Booth's escape route--the villain's various guises have included transvestitism and a new identity as a magician who is the world's greatest escape artist--and the climax is a balloon flight, with Cosgrove chasing Booth over the Atlantic. Sprightly period nonsense--author George O'Toole (The Private Sector) has even gussied up his name to add to the mid-century flavor; more for fans of historical hoke than true Lincoln-ists.