At the age of thirty-one, living as a penniless exile in Berlin, Vladimir Nabokov composed, in Russian, a novel called "Camera Obscura," which he published serially in an émigré journal in 1930. Five years later, the book was translated into English by a woman named Winifred Roy, for the British publisher John Long. But Nabokov claimed that Roy's translation was “sloppy” and “full of blunders” and, when approached by a publisher about an American edition in 1938, he chose to retranslate the novel himself. The new version (Nabokov’s first English literary production), which he retitled "Laughter in the Dark," is a masterful short novel about an older man's obsession with a young girl, and is today considered an important precursor to "Lolita."

I'd always been curious to know how extensively Nabokov revised "Camera Obscura" when turning it into "Laughter in the Dark." The mastery of the latter suggested that it was a considerably more mature Nabokov who dreamed up, for instance, the insouciant opening paragraph of “Laughter,” which, by giving away the story, alerts readers that the novel is about more than narrative suspense:

Once upon a time there lived in Berlin, Germany, a man called Albinus. He was rich, respectable, happy; one day he abandoned his wife for the sake of a youthful mistress; he loved; was not loved; and his life ended in disaster.

Did Nabokov come up with these lines in his original Russian version, which he hastily scribbled in six months? And what about other Nabokovian touches, like when Albinus, the story’s hero, first meets Margot, the teen-aged object of his obsession, in a movie theatre where she works as an usher, and the movie being shown foreshadows the novel’s violent ending? (“He had come in at the end of a film: a girl was receding among tumbled furniture before a masked man with a gun. There was no interest whatever in watching happenings which he could not understand since he had not yet seen their beginning.”) That glimpse of the couple’s fatal, final confrontation, suggestive of the doomful implacability of fate, always struck me as a hallmark of the mature Nabokov, the Nabokov who would come to full flower in “Lolita,” “Pale Fire,” and “Ada.” Or was he already capable of such effects when he wrote the original Russian version?

I knew that there were differences between the two editions. In his 1990 biography of Nabokov, Brian Boyd wrote that Nabokov had “revamped the opening,” “improved the mechanism by which hero meets villain,” and “redesigned the means by which hero discovers the villainy of villain and heroine.” David Rampton’s excellent 2012 book, “Vladimir Nabokov: A Literary Life,” provided more detailed insight. But I wanted to know precisely how Nabokov had “revamped” and “improved” the original, and why.

The obvious solution would be to buy or borrow a copy of Roy's translation and compare it to Nabokov's, but that’s almost impossible to do. “Camera Obscura” sold only a handful of copies upon its release, and the London warehouse containing the unsold stock was destroyed by German bombs during the Second World War. (According to the French scholar Christine Raguet-Bouvart, only seven copies still exist, all in rare-book archives and private collections across the globe.) I've kept my eye out for the novel for thirty years in used bookstores, thrift shops, flea markets, and, in recent years, on eBay. All to no avail.

So I finally resolved to visit the copy held in the New York Public Library’s Berg Collection, which houses Nabokov’s papers and is open only to credentialed Nabokov scholars. My ancient master’s thesis on his English-language novels and a mumbled story about a research project on "Laughter in the Dark" won me an appointment, and on a recent day I visited the Berg’s frigid reading room on the fifth floor of the library's main branch. For the Nabokov fan, the place is surreal: open on the table in front of the man beside me was a binder with plastic sleeves holding the original “Speak, Memory" manuscript, handwritten in pencil on Nabokov’s famous index cards.

The librarian emerged from a back room, and on a V-shaped foam pedestal he placed in front of me Roy's ultra-rare translation—a hardback with a cover bearing a ludicrous romance-fiction illustration that I was familiar with from Boyd's biography, where it was reprinted. I flipped immediately to the first page. Far from the elegant and mischievous “Once upon a time” opening, I was confronted with a mystifying, clumsy passage about a cartoonist named Robert Horn (in “Laughter,” he becomes the much more felicitously named villain Axel Rex) and his cartoon creation, a Mickey Mouse-style guinea pig named Cheepy, who was (wisely) excised completely from “Laughter.” The following four pages detailed a copyright lawsuit levelled by Horn against a company that used an unauthorized version of Cheepy for an ad. The book’s hero, the hapless Albinus, is introduced into the story as a picture expert called in to consult on the case.

A thin blue vertical fountain-pen stroke ran down through this endless opening, and I fleetingly wondered who could have dared to deface such a rare book. Then, when I turned the page and saw a few scribbled words in that same blue pen in the margin, I realized with slow amazement that this copy of “Camera Obscura” was not simply a rare edition procured by the Berg to round out Nabokov’s archive; it was Nabokov’s personal copy—the very copy in which he had revised virtually every page of Roy’s version in a storm of handwritten additions, crabbed interlineations, carat-sprinkled paragraphs, and bursts of inspiration.

Nabokov was notorious for never showing early drafts of his work to journalists or scholars. He compared doing so to "passing around samples of one's sputum," and he was careful, in his constant grooming of his Olympian public image, to leave no embarrassing first drafts for posthumous study. The one exception was his embryonic version of "Original of Laura," which was left uncompleted after Nabokov’s death, and which he had instructed his widow, Vera, to destroy. She couldn’t bring herself to do so and, some years after she died, their son, Dmitri, allowed the unfinished book to be published. But that was a curated event, and Nabokov had already revised much of the draft copy. The Berg Collection version of “Camera,” on the other hand, provides an unmediated look at the Master at work, removing dead and dull passages, fixing inept or lame plot developments, eradicating longueurs, and seeking out opportunities to sharpen imagery or provide deeper insight into a character’s motivation. (Indeed, the movie-theatre foreshadowing proved to be unique to the second version.) Interestingly, Nabokov was indecisive about how old the novel’s girl should be. In the Roy version, Albinus guesses that she is “seventeen or eighteen”; in the Berg Collection copy, Nabokov crossed out that line and wrote “Eighteen.” But in the final version of “Laughter” he settled on the considerably more shocking sixteen. Even minute additions—like Nabokov’s reference to the “frozen wave” of the mussed-up carpet in the book’s final, terrible tableau (Albinus dead on the floor with the gun underneath him, Margot fleeing through the open door)—provided a frisson of excitement, as did the apparent speed with which Nabokov composed his superb additions, some of which are scribbled almost illegibly.