MATTHEW PEARL'S second novel is based on what he calls 'one of literary history's most persistent gaps.' Edgar Allan Poe died, Pearl tells us, 'at the age of 40 in a Baltimore hospital on Oct. 7, 1849, four days after being found in distress at Ryan's inn and tavern.' The stubbornly unexplained gap occurred in the five days preceding his appearance at the tavern. Poe was supposed to be almost anywhere other than Baltimore: he was traveling from Richmond to New York with a planned stop in Philadelphia, not Baltimore. No one knows how he came to be in the city – or, for that matter, how he ended up at the tavern. For some of us, this pretty much describes a really great Saturday night, but when it happens to the master of darkness, just days before his untimely death, it has the makings of a mystery. Pearl takes us back to those few lost days through the inquiries of Quentin Clark, a Poe-mad young Baltimorean who is dismayed not just by the writer's death but by the press's apathetic reponse to the news. Clark takes it upon himself to look into matters and rectify this slight to his hero. The trouble is, Clark is a stock character from the world of commercial thrillers: a man with a lot to lose, imperiled by his own obsession. Engaged to a beautiful young woman, the son of wealthy and very proper parents and pursuing a career as a lawyer, he may sacrifice them all to his devotion to Poe. Clark haunts the writer's grave, visits the hospital where he lay dying and tracks down the Poe cousins. But wherever he turns, he's met with indifference or outright obstruction. Finally, in desperation, he turns to another source of information: the pages of a book. Clark has always admired Poe's 'Murders in the Rue Morgue' and the other mysteries featuring C. Auguste Dupin, the brilliant Frenchman who solves crimes too baffling for the Paris police. 'Dupin's reasoning followed a method Poe called ratiocination,' Clark reminds himself, 'employing one's imagination to achieve analysis, and one's analysis to climb the heights of imagination.' When Clark stumbles on a newspaper item suggesting that Dupin was based on a real Frenchman, he promptly takes off for the Continent. Of course, there turns out to be more than one candidate for this honor, and soon a couple of testy Frenchmen are racing back to America, eager to snatch whatever glory they might from Poe's death. Baroquely orchestrated complications ensue, up to and including a threat to the future of the French republic. As he demonstrated in his serial-killers-and-philosophers best seller, 'The Dante Club,' Pearl is a fine scene-setter and a resolute, if not always inspired, plotter. 'The Poe Shadow' is thick with intrigue and thicker still with carefully researched (and ostentatiously displayed) details. Pearl, who taught literature at Harvard before embarking on his literary career, sometimes displays a wonderfully knowing tone, and enjoys playing with 19th-century lingo. When a Baltimore police officer asks Clark if he has a wife and is told that he has a fiancee, the officer warns: 'You should have much to occupy yourself without needing to think of this unhappy affair, then. Or your sweetheart might give you the mitten.' Sadly, Pearl's plot is not all sweethearts and mittens. With its bewildered narrator and its attempt to marry the rational and the spooky, 'The Poe Shadow' seems to be modeled on Poe's own writing, but it's missing a crucial element: brevity. Although Pearl has a real affinity for 19th-century America, he overwhelms the strengths of his book with a hurricane of ersatz Victorian prose. He doesn't just disinter Poe's story; he disinters the language of Poe's time. After a while, you feel like you're trapped in a sepia-toned faux-daguerrotype. Pearl has created a museum rather than a world. And no one lives in a museum.