A first novel is like spring lamb, tender and pink. Athenas that leap from the writer’s head armor-clad—Marilynne Robinson’s “Housekeeping,” say—may not count. Better to find a novel that requires indulgence—Fitzgerald’s “This Side of Paradise” or Agee’s “Let Us Now Praise Famous Men.” Débuts, even from much tougher writers, allow the reader to enjoy a guilty sense of paternalism: you protect débuts like Naipaul’s droll “Miguel Street,” or James’s thin “Daisy Miller,” or Coetzee’s compacted, miserable “Dusklands,” from the full force of your regular expectations.

But then there are the real treasures, the rehearsals that never got published, the artifacts that invite you to reconstruct what an author wanted to do, before she did it. Did Jane Austen know, sitting with “Elinor and Marianne” on her lap, that she would keep writing, that she would never stop, that the rudiments on her page would refine themselves into anything like “Pride and Prejudice”? Juvenilia inverts the old urge to go back and tell a writer who died in obscurity “Hey man, we all loved ‘Moby-Dick.’ ” You dream of congratulating the young Austen.

Even Vladimir Nabokov, the high priest of readerly hygiene, occasionally allowed himself this kind of communion. He may have forbidden his Cornell students from identifying or sympathizing with any fictional characters. But identifying with the author was a different matter. Nabokov told his students of writers’ travails, urging them to consider the number of days Flaubert took to write the scene with Emma and Leon in the Lion d’Or. He even acted out Gogol’s death throes at the podium, waggling his nose and asking his students to imagine the leeches that were attached to the dying writer’s larger, more famous proboscis.

Now we have an invitation to root for the young Nabokov. His first major effort, “The Tragedy of Mister Morn,” has been translated for the first time. “Mister Morn” is a verse play, but its speeches are bright with Nabokovian gems: “within him is that spark / that scarlet comma of contamination,” says one character, the revolutionary leader Tremens, of a former firebrand gone dull. Reading this tale of an exiled king from a fantasy kingdom, one wonders if Nabokov realized, in 1924, that he was writing the first draft of “Pale Fire” (1962).

We do know that he was trying to get a career started when he wrote the play. Nabokov’s family had fled Russia in 1919; he had attended Cambridge and then joined his family in Berlin; his father, a politician in exile, was killed by right-wing Russian terrorists in 1922; and by December, 1923, the rump of the family had temporarily relocated to Prague. As Brian Boyd relates in his authoritative biography, the Nabokovs were seven people in a three-bedroom apartment. Vladimir and his brother Kirill shared a couch; at night, bedbugs crawled up the walls in order to fling themselves down on the two young men from on high.

It’s hard to believe that Nabokov was ever young. Years later he would show up in the United States, his bags crammed with ten novels written in Russian, and one already written in English. But here he was in Prague, the young poet who still went by the pen name Sirin, staying up till five or six in the morning, writing by candlelight. He was impressed with his own exhaustion. In letters to Véra—his future wife—he reports that his head thunders like a bowling alley. Fame is in the forecast. He goes to a party, and an elderly woman asks him:

Do you go to high school here? I: !!! Woman: Oh, I’m sorry, you have such a young face. So you’ll be starting lectures? What faculty? I (with a melancholy smile): I graduated two years ago, in science and literature. Woman (lost): Oh, so you’ve been working. I: For the Muse. Woman (picks up): So you’re a poet. Been writing long? Tell me, have you read Aldanov? Interesting, isn’t he? In these difficult times, books are a great help. If you take up Voloshin or Sirin, for instance, your spirits just lift at once. But nowadays books are so expensive. I: Yes, very expensive. And modestly moved off incognito. Amusing conversation? I’ve set it down word for word.

He was more than happy to consider himself a well-kept secret. Everything was still in him.

Back in Berlin with his manuscript, Nabokov found that money was tight. The Russian literary community was drifting to Paris. No one wanted to perform “The Tragedy of Mister Morn,” and a Shakespearean tragedy did not interest the émigré press. Nabokov next tried a more conventional début. “Mary” is a semi-autobiographical novel set in a real milieu in a real city; for the protagonist, Berlin is shot through with memories of teen-age romance, in Russia. Finally, Nabokov had got a viable start to his career. Reviewers praised Sirin’s rapturous use of detail—a future commonplace of Nabokov criticism.

It’s “Mister Morn,” however, that seems most enticingly predictive of Nabokov’s great work. The flutter of magic, the avuncular twinkle, the B-movie danger—it’s all here. The things that make us love Nabokov or tire of him can all be found in “Mister Morn,” at least in chrysalis form. A bildungsroman like “Mary” may preview the teen-age romance stirring in the latter chapters of “Speak, Memory.” But the childhood romance of that memoir’s earlier chapters—the same Annabel-by-the-sea memories that get “Lolita” revving—could never take flight without the wistful, distracted tone of voice he practiced in “Mister Morn.” Every speech in the play seems to take some kind of renunciation as its occasion. It may be a weakness that the plot twists not at the middle but at the beginning; but the idea that a benevolent king would rule his kingdom incognito comes straight from the taproot of Nabokov’s most insistent theoretical claim, that all fiction is fantasy.