In “Is that Kafka? 99 Finds,” Reiner Stach curates a collection of artifacts from the author’s life, including half-finished stories that are known to scholars but haven’t quite found their rightful place in the canon. Photograph by Fine Art Images / Heritage Images / Getty

The stories of Franz Kafka have long since passed into the proverbial, the kind of work you need not have read in order to know. Just as we speak of high-stakes intrigues as “Shakespearean,” and storms as possessing “Biblical proportions”—whether or not we’ve read “Julius Caesar” or the Book of Job—the qualities of the “Kafkaesque” are familiar to us not from reading Kafka’s stories but from the stories we experience every day. We use “Kafkaesque” to describe encounters with banally evil customer-service agents; it’s the shorthand that op-ed writers use to protest the dark dealings of the state. For a writer, it’s a dubious honor to be thus referenced but not quite read: it’s a way to remain forever present and forever misunderstood.

To help reverse this drift of Kafka’s reputation, Reiner Stach has curated a collection of artifacts from the author’s life in his latest book, “Is that Kafka? 99 Finds.” The book, translated from the German by Kurt Beals, is a crowd-pleasing encore to Stach’s monumental three-volume biography of the writer. Along with minimal commentary, he submits ninety-nine numbered exhibition items—documents, photographs, objects, scribbles, and doodles—for our consideration. The result is a box of fancy Austro-Hungarian chocolates: the floor-plan to the Kafka family apartment (the setting for “The Metamorphosis”); facsimiles of Freudian slips in Kafka’s handwritten manuscripts; a diagram of his workout regimen; his sincere proposal for a utopian commune; an advertisement for his first book that includes such catchy marketing pitches as “until now, his compulsive tendency to continually revise his literary works has prevented him from publishing any books.” We get a reprint of an adorable postcard Kafka wrote to his little sister, and the lyrics to his favorite song, “Now Farewell, You Little Alley.” Kafka was a charmer and a flirt, the kind of guy who gave his parents’ housekeeper a gift of an umbrella with candies hanging from the tips. One of his girlfriends nicknamed him Frank. He was adored, apparently, by all—with the exception of one man, a physician named Ernst, who appears in this volume wearing a white lab coat over a military uniform, and clutching a sinister turn-of-the-century medical device. (No. 12: “Kafka’s Only Enemy.”)

There are masterpieces in this book. Stach gives us the full text of a 1917 letter from a reader, one Dr. Siegfried Wolff, who complains that he can’t understand the meaning of “The Metamorphosis,” and, what’s worse, his whole extended family is similarly perplexed about the story, and they look to him, as “the Doctor in the family,” for an explanation. “Only you can help me,” he writes to Kafka. “You must; because you’re the one who got me into this mess.” Stach, aware that this letter sounds like a joke from one of Kafka’s friends, has done the legwork to track down this Siegfried Wolff, and can confirm that he was a real person.

Even amateur Kafkaists, who may already know about most of these finds, will get their first chance to see faithful reprints and transcripts of the things themselves, and draw their own conclusions. Perhaps you already know that Kafka, along with his friend Max Brod, invented the concept of budget travel guides for tourists. But how many of us have had the pleasure of reading the full six-part outline of their book proposal for this series? (Title: “On the Cheap,” complete with a proto-Nike motto: “Just Dare.”) Readers familiar with “Amerika”—Kafka’s unfinished novel that includes a description of a bridge that connects New York City with Boston—will be delighted to find this note from the “On the Cheap” outline: “No comprehensive geography, only routes.”

But the gems of this collection are the half-finished Kafka stories that are known to scholars but haven’t quite found their rightful place in the canon. Item No. 61, which Stach titles “Kafka Dreams of an Olympic Victory,” is a must-read for Kafka buffs and fans of existential bewilderment alike. Here is a fragment of that fragment:

Honored guests at this banquet! It is true that I have a set a world record, but if you were to ask me how I achieved it, I would be unable to answer you to your satisfaction. You see, I actually cannot swim at all. I have always wanted to learn, but I have never found the opportunity. So how did it happen that my fatherland sent me to the Olympiad? That is exactly the question that concerns me, too.

It’s a question that concerns all of us, or it ought to—and Stach gives it pride of place here. He also uses this piece to offer us a useful look at Kafka’s editorial process. Stach points out that in the first draft of this story, Kafka identifies the narrator as the winner of the fifteen-hundred-metre event at the games in Antwerp—the real-life setting of the 1920 Summer Olympics. But in a second draft, Kafka substituted an “X” for Antwerp, and omitted any mention of fifteen-hundred metres. It’s a juicy Kafka edit, a small look at how he artfully tweaked literary realism.

Many of these ninety-nine finds may indeed help “overturn the stereotypical version of the tortured neurotic,” as the cover copy puts it, but there are also those that reinforce it. Kafka’s letter describing a harrowing “night of mice,” for instance, and his diary entry, written in code, lamenting that “s. [sex] crushes me.” And then there’s item No. 96, the full texts of his notorious last wills, in which he requested not only the burning of his unpublished work (which was most of his work at that time), but added that he would ideally like his few published works also destroyed so that he would be forgotten completely. Still, this book does show us that Kafka was more than a tortured neurotic—or, rather, it demonstrates that even tortured neurotics can be great company. As if to prove that Kafka was, as we say these days, the kind of guy you’d want to have a beer with, Stach dutifully catalogues Kafka’s beer drinking history. (No. 9: “Kafka Drinks Beer.”)

This is one of the challenges of Kafka biography: humanizing a writer who wasn’t terribly attached to conventionally human points of view. Kafka, after all, is a writer who thoroughly destabilized the line between human and critter. In his biography, Stach makes a convincing argument for the pervasive, yet unspoken, influences of the First World War on Kafka’s work; and yet it’s exactly that seemingly ahistorical—because purely animal—consciousness that makes Kafka’s art feel uncannily true. Situating Kafka in history can have the unfortunate quality of explaining a joke: even if it doesn’t spoil the effect, it still seems mostly beside the point. As thrilling, and sometimes enlightening, as it might be for Kafka readers to meet the “real” Kafka, handsome suits and all, they will probably continue to hold the belief that the truest Kafka was the mind who shut the door on the wide world and recorded the thoughts of an inquisitive dog.