The Hemingway Hoax by Joe Haldeman

The Hemingway Hoax is a Hugo- and Nebula-winning novella that weaves an intricate plot of a fake Hemingway manuscript with time travel, multiple universes, and the potential destruction of the omniverse itself.Hemingway's first wife, Hadley, lost a bag containing the manuscript of his first novel on a Parisian train. In 1996, John Baird, a renowned Hemingway scholar, decides to use that loss to account for a fake manuscript he creates.Little does Baird suspect that his attempt to pass off the forgery as a recovered Hemingway manuscript will take him on a journey involving parallel universes and time travel. For Hemingway's reputation is intricately linked to the fate of multiple worlds in the omniverse and any attempt to change that can have disastrous consequences.