Trying to sort through the acres of contradictory evidence about how Edgar Allan Poe lived and died, one is inevitably reminded of a bit of advice found in his satirical short story “The System of Dr. Tarr and Professor Fether”: “Believe nothing you hear, and only half that you see.”

That’s certainly something to keep in mind when considering some of the more unreliable witnesses who left behind accounts that for generations have shaped—or misshaped—our view of the enigmatic writer’s stormy life and mysterious death.

When I began working on the biography A Mystery of Mysteries: The Death and Life of Edgar Allan Poe, I had no doubt about who the mangler-in-chief was when it came to twisting our perception of the life and personality of Poe, author of such influential horror stories as “The Tell-Tale Heart,” “The Fall of the House of Usher,” “The Pit and the Pendulum,” “The Masque of the Red Death,” and “The Cask of Amontillado.”

That would be the jealous and vengeful poet and editor Rufus Griswold. The day after Poe’s funeral, on October 8, 1849, in Baltimore’s small Westminster Presbyterian Cemetery, Griswold buried him again, under a mountain of grotesque lies, distortions, and fabrications. Nursing grudges against Poe, he wrote an obituary that appeared in the evening edition of the New-York Tribune. Griswold had no intention of honoring any prohibitions on speaking ill of the dead.

“Edgar Allan Poe is dead,” the blast at the recently departed began. “He died in Baltimore the day before yesterday. This announcement will startle many, but few will be grieved by it.” That was one of the kinder passages in Griswold’s brutal attack. And it was just the first salvo. Griswold continued to flail obsessively at the corpse in future printed assaults, depicting Poe as, among other things, immoral, arrogant, unbalanced, dishonest, envious, conceited, and dishonorable. He created a wildly inaccurate image of Poe that hasn’t been completely dispelled to this day.

Still, a pathetic irony emerged from examining everything Griswold wrote about Poe. All of the vicious volleys he aimed at Poe couldn’t help rebounding and hitting an unintended target—Griswold himself. He did as much lasting harm to his own reputation as he did to Poe’s, perhaps more. Griswold wanted to be remembered for his art as a poet and litterateur, having tried to establish himself as an arbiter of literary taste with the anthology Poets and Poetry of America. Instead, if he’s known for anything today, it’s for the art of character assassination. He’s remembered only because Poe is remembered, and celebrated, for inventing the modern horror tale and the detective story, as well as for composing such haunting poems as “The Raven,” “Annabel Lee,” and “The Bells.”

This backlash pattern began early, when Poe’s French champion, the poet and critic Charles Baudelaire, labeled Griswold “a pedagogic vampire.” He also denounced Griswold as a cur, asking, “Does there not exist in America an ordinance to keep dogs out of cemeteries?”

The vengeful poet and editor Rufus Griswold depicted Poe as immoral, arrogant, unbalanced, dishonest, envious, conceited, and dishonorable.

While Griswold was the unreliable witness primarily responsible for the false view of how Poe lived, it was a doctor, John J. Moran, who hopelessly muddled the circumstances of his death. A Poe enthusiast since childhood, I well understood that Moran’s testimony was shaky on many points. But I didn’t completely grasp how badly the good doctor had confused what can, sarcastically, only be called “the record.”

Found semiconscious and delirious outside an Election Day polling place in Baltimore on the damp, chilly afternoon of October 3, Poe, 40, was taken to Washington University Hospital, where Moran, in his mid-20s, was a resident physician. We know that Poe lingered until breathing his last in the early hours of October 7.

Since then, Moran has been our primary source for details about Poe’s deathbed days. Every aspect of his testimony, including Poe’s supposed last words, must be viewed with a high degree of skepticism. Moran wrote three accounts of Poe’s final days. Side-by-side-by-side comparison casts all of his testimony in doubt, revealing a staggering number of discrepancies and contradictions.

In one account, he has Poe yelling out the name “Reynolds” for three to six hours. In another, he makes no mention of this at all and gives the Reynolds name to a family living near the hospital. He moved the time of death from one account to another. He greatly altered the conversation he claimed to have had with Poe. He went so far as to change Poe’s final words.

Given the dizzying number of theories about how Poe died—everything from binge drinking, heart disease, and carbon-monoxide poisoning to a brain tumor, murder, and rabies—and the fact that there was no death certificate or autopsy, Moran is the one person we needed to be precise and trustworthy in his memories and observations. Instead, going on lecture tours and hoping to launch a literary career, Moran offered accounts that increasingly read like works of fiction—and very bad fiction at that, full of melodramatic and unbelievable dialogue.

One of the goals of A Mystery of Mysteries is to shatter the many myths and misconceptions about Poe. That means dealing with the great disservice Griswold and Moran did to him. Although motivated by different factors, they made quite the misinformation team: Griswold leaving us with a noxious pile of infamy, Moran leaving us with a frustrating pile of uncertainty.

When Griswold’s lies are exposed, dissected, and obliterated, Poe emerges as an infinitely richer, more complex figure: an exacting and dedicated artist who could be quite courtly, engaging, and, yes, funny. He was not who even many ardent fans think he was: the hollow-eyed, ever gloomy guy haunting graveyards and spinning out wild visions in the grip of intoxication. And he certainly wasn’t the immoral, unbalanced wretch Griswold tried to make him out to be.

When Moran’s massive contradictions are brought to light, the literary sleuth can concentrate on what little real evidence does exist. Does A Mystery of Mysteries settle on what seems a logical and convincing cause for Poe’s death? Absolutely. Is there unassailable proof? Absolutely not. Such an irresponsible claim would require equal parts invention and fabrication, and Griswold and Moran gave us quite enough of that.

Mark Dawidziak’s A Mystery of Mysteries: The Death and Life of Edgar Allan Poe will be published on February 14 by St. Martin’s