Wren

Wren is an archivist, researcher and translator employed by Aloysius Pendergast for various investigations and personal projects. Pendergast often consults him during the course of his cases, usually visiting him at his preferred haunt in the basement of the New York Public Library.

Wren's first name is unknown even to those closest to him—including Pendergast.

Appearance and Mannerisms
Wren is a wizened, ancient-looking man with long, wild white hair and bright black (originally yellow) eyes. Endless hours spent in the depths of the library's archives have left his skin the color of old parchment, and he has been said to smell faintly of dust and binding paste. He has a high voice and speaks in an old-fashioned, poetic manner. Despite his age, he is mentally sharp and is an expert researcher.

Wren is a registered professional researcher at the library. He appears to make his living researching things, although it is unclear if he has clients besides Pendergast. When Pendergast visits Wren, he often brings along rare books and manuscripts for Wren's perusal. Wren also repairs damaged books for the library, although whether this is his job is not known.

Wren's family and friends, if any, are never mentioned. He maintains a friendly professional relationship with Pendergast, and often calls him hypocrite lecteur, a reference to the poem "Au lecteur" by Charles Baudelaire, which was also quoted in T.S. Eliot's "The Wasteland".

The Cabinet of Curiosities
Wren was introduced for the first time in The Cabinet of Curiosities. Pendergast visits Wren at the New York Public Library and asks him to research information about Manhattan house deeds. He brings Wren an 14th-century illuminated manuscript and warns him to research the deeds before studying the manuscript, referring to an unknown incident that occurred two years earlier.

Still Life With Crows
Wren catalogued the Riverside Drive collection of "curiosities" over an 8-week period. During this time he felt watched, and heard the light swift steps of a child.

For the privilege of restoring Sitting Bull's ledger, Wren locates the article "An Account of the Dodge Forty-Fives" by Isaiah Draper from the New York Public Library. The article was needed by Agent Pendergast for the investigation into the Curse of the Forty-Fives.

Brimstone
Wren made a rare appearance outside of the library to deliver a DVD to Pendergast's Riverside Drive mansion containing a catalogued indexed inventory of the mansion's collections.

Cemetery Dance
During the events of Cemetery Dance, Wren provided Pendergast with a detailed history of the Ville des Zirondelles and its inhabitants in exchange for a set of three rare early Arkham House publishings. He later uncovered and passed on a series of old newspaper clippings about the Ville and its connection to a series of murders, and even produced a map helping Pendergast and D'Agosta find one of the graves.

Cold Vengeance
When Pendergast began looking into Helen's family history during the events of Cold Vengeance, he turned to Wren to trace her lineage, which revealed that Helen's great-uncle was a notorious Nazi war criminal and refugee. Wren described the project as the one time he almost wished his research had been a failure.