Arkady Dolgoruky, the first-person narrator, is the natural son of Versilov,

a cold and proud man, haughty and negligent toward me, who..., having fathered me and abandoned me among strangers, not only did not know me at all, but never even repented of it

.
Arkady suffers deeply from his father’s indifference, not least because the latter has taken his mother with him and reduced the young man to a state of acute social distress, as his status as an illegitimate son is known to all.

I was like an outcast...
and I had decided to renounce them all and withdraw once and for all into my own life

.
What draws the young man, who has now completed his secondary studies, out of his isolation is a letter from Versilov inviting him to Petersburg.
The first part of the novel recounts Arkady’s encounter with the complex and elusive figure of his father: a fraught relationship, also because

that man was nothing but my dream, the dream of my childhood years.
Thus I had invented him myself, whereas in reality he proved to be different, fallen so far below my fantasy

.
Yet Versilov is not the sole center of Arkady’s life.
The young man finds himself caught within a veritable “enigma,” woven of characters, relationships, and events, amid which he feels ill at ease with his rigid, solitary, and proud disposition.
Much to his regret, he must acknowledge that people have multiple faces, that interpersonal relationships are often ambiguous, and that there is a “sacrosanct axiom” in Pushkin’s famous verse: “dearer to me than base truth / is the deception that transfigures us.”
In the second part of the novel, Arkady appears to have accepted this reality.
He leads a dissipated life, devoted to gambling, drinking, and women, while neglecting his mother and sister, whom he has only just met.
This might be an ordinary phase in an adolescent’s life, were it not for the fact that Arkady carries a terrible secret: sewn into his coat is a document in which Katerina Nikolaevna, Versilov’s former lover, formulated a plan to have her father declared legally incompetent—a wealthy, elderly prince to whom, moreover, Arkady is deeply attached.
The discovery of this document would prompt the prince to disinherit his daughter and would favor the aspirations of Arkady’s half-sister, who wishes to marry the old aristocrat.
To complicate matters, Arkady is in love with Katerina and cannot bear to betray her.
Furthermore, he is fond of his half-sister, fascinated by her intellect and strong character.
Everyone suspects that the young man possesses the document, and so they cajole him with words and gestures that the naive Arkady misinterprets as genuine acts of friendship and even love.
It is difficult to navigate this web of intrigue, especially when one lacks a clear perception of good and evil and when people are neither clearly wicked nor purely virtuous.
What reigns is “the soul of a spider”—namely, that man

can cherish in his soul the loftiest ideal alongside the greatest baseness, and all in perfectly good faith

.
Yet Arkady too is seized by “ignominious thoughts”—for instance, using the document in his possession to win Katerina’s love.

Where, then, had all of this come from, already so prepared? And this, because I had the soul of a spider! It means that everything had sprouted long ago and lay in my corrupt heart, lay in my desire

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And it is precisely Arkady’s weakness, his yielding to the pull of evil, that precipitates the crisis in the third part of the novel.
The young man is himself duped by criminals who secretly steal the document from him and attempt to blackmail Katerina.
To his horror, the youth later discovers that they are in league with Versilov..
Versilov’s split personality confronts the young man as a “broken image,” all the more so after an intense, long-awaited conversation in which Versilov had professed to his son his love for Arkady’s mother, only to subsequently send Katerina a formal marriage proposal.
Who, then, is his father really? Perhaps merely a man driven by whim, by unchecked vanity, Arkady thinks.
The disillusionment with the father figure is complete.
Arkady is no longer an adolescent.

The Adolescent is the author’s most contemporary novel.
Several elements contribute to this: the modernity of the father-son relationship, the Pirandellian theme of duplicity, the detective-story elements of the plot, which is full of twists and turns and frequently leaves the reader in suspense as to what will follow.
The book’s greatest merit lies precisely in its tight pacing, which leaves little room for philosophical disquisitions, as is so often the case in the author’s other novels.
Beyond Dostoevsky’s well-known skill in constructing dialogue, what is striking is the author’s ability to mirror duplicity in the very structure of the sentence: for example, chapters unfailingly close with the image of a contradiction, of an ‘other,’ delineated in just a few sparse strokes.

Why read it? It is one of Dostoevsky’s finest novels, insufficiently appreciated perhaps because it does not foreground philosophical and religious themes.