Early in Chalk: The Art and Erasure of Cy Twombly, author Joshua Rivkin confesses that the book “is not a biography. This is something, I hope, stranger and more personal.” What, a reader may wonder, could be more personal than a biography? Chalk is one answer to that riddle.

Cy Twombly, a prominent abstract artist whose popularity has only grown since his death in 2011, is best known for his large, abstract paintings—“passionate splashes of color … curves of white chalk looping through darkness.” Rivkin describes the artist’s work as an actualization of “the bewildering slipstream between thinking and feeling.” Twombly’s most staunch admirers are ecstatically unnerved by his canvases; a woman once spontaneously kissed one painting, leaving behind a lipsticked print. (She was, as lovers often are, unrepentant.) But, outside the art world, Twombly’s messy, seemingly thoughtless style inspired confusion and disdain. His scratchy, hectic paintings have led the unimaginative to shrug, “My kid could do that.”

Rivkin is intensely focused on the “complex arrangements of love and domesticity” that filled Twombly’s life—from his early love affair with a married Robert Rauschenberg, to his impenetrable and improbable marriage to the Italian heiress Tatiana Franchetti, to his decades-long entwinement with his assistant and rumored paramour, Nicola del Roscio.

I came to Chalk with an adoring familiarity with Twombly’s work but almost no knowledge of his life. He would have wanted it this way, as he was mysterious with reporters and often secretive with even his closest friends. When the writer Edmund White asked him what his parents did, Twombly said, “They were Sicilian ceramicists.” (This was a lie.) When asked how many paintings would be in his MoMA show, he said, without blinking, “Forty thousand.” The Twombly Foundation, under the presidency of del Roscio, is faithful to the artist’s recalcitrance. Yet Rivkin takes the position that “Life and art are never separate conversations. It’s easy to read—and overread—the biographical in Twombly’s art. He practically dares you.”

Rivkin’s torrid relationship with the Twombly Foundation becomes, by necessity, a part of the plot. After several threats, the foundation refused to license any images of Twombly or his work for Chalk. (The few photographs that do appear were authorized by other estates and archives.) In the end, the foundation (more specifically, del Roscio) was appalled and annoyed by Rivkin’s project. Attorneys appear. Threatening letters appear.

Yet part of the excellence of this biography (I respectfully refuse Rivkin’s refusal of the term) is that it alchemizes this challenge into an asset. The book is more personal than a biography because the biographer, who is already an accomplished poet, offers details from his own life as they mirror that of the artist. Though it may sound like misplaced exhibitionism, Rivkin’s vulnerability is a gift. Because so many details of Twombly’s life were erased, withheld, or obscured, Rivkin’s brief autobiographical interludes seem to transform those erasures from an absence to a presence. In this respect, at least, Rivkin is right to say that Chalk is not a biography. Portraiture is always an act of triangulation; a biography, no matter how removed the writer may try to be, is always covered in fingerprints.

Twombly, at once Southern and queer and closeted and famous, seemed animated by equal parts expression and secrecy. His paintings often contained text—some legible, some erased, some scribbled out—and he titled much of his work “Untitled,” followed by a piece of text hovering between parentheses. An undeniable and erotic charge courses through much of Twombly’s work, one that has animated many serious examinations by art historians and critics. “In one version of The Birth of Venus, his variations on the iconic, half-naked goddess on a scallop rising from the sea, he layers a hundred breasts like petals of blooming flower, a bouquet.” In another collage, a response to a da Vinci study of heterosexual copulation, Twombly isolates the male anatomy—“From its tip, a cascade of lines stream down the length of the page. A fountain. A chandelier … The word ‘reject’ is scrawled beside the image.” Horse and human penises are featured prominently in a Twombly collage that Rauschenberg owned, vaginal imagery populates a series of drawings done in Capri, and disembodied phalluses float throughout the rest of his work. “To say that one can read Twombly’s own wants or anxieties from these pictures is a mistake,” Rivkin qualifies during the section of the book attempting to untangle all this visual innuendo. “That doesn’t mean his obsessions don’t matter.”

During a chapter about anticipating the birth of Twombly’s only son, Rivkin folds a few details of his own wife’s pregnancy. While expecting his first son and having a summer fling with a “beautiful Canadian boy,” Twombly made twenty-four drawings in a single day, Poems to the Sea. Rivkin spends much time with Poems to the Sea—in one drawing Rivkin notices “a question mark drawn inside a square … I love that mark. A little frame around all the uncertainties—set apart and held up and contained. The mark like a buoy in a turbulent sea.” Later Rivkin includes a story of Twombly, who was a largely absent father, speaking of his son to a friend in Virginia: “I don’t know where he slept.” When Rivkin asks, “What artist hasn’t wished to undo all the bounds that hold them steady to the earth?” he is not only referring to his subject, but implicating himself. The stability and instability inherent in both parenthood and artistry, and the way those two roles—father and artist—were often at odds for Twombly, has an obvious personal resonance to Rivkin.

Authors who write sentences as playful and passionate as Rivkin’s are anomalous in the world of scholarly nonfiction. A biographer can easily slip into a work-horse automation for pages or chapters at a time, but Rivkin rarely (if ever) does so. A dark night is “a purple-bruise, a crow belly.” A marital spat shows “distance and anger nested like cup and saucer.” By completing and publishing this work, despite threats of litigation from the Twombly Foundation, Rivkin is “tilting at windmills in a hurricane.” At times, the text scatters into vivid fragments, a linguistic reflection of Twombly’s work. The reader can infer that the artist’s style has changed Rivkin’s own, shifting it like a house off its foundation. If there is a flaw of this approach, it is that the text sometimes swerves into lyrical saturation. But for the most part, buoyed with insights from hundreds of writers from Albee to Woolf, Rivkin stays afloat.

Rivkin’s quest for information while living in Rome, a place which runs “on its own languorous, maddening time,” becomes its own plotline in Chalk. Putting aside his role as devout biographer, Rivkin steps into the narrative as a determined but slightly mad detective. He is determined to establish and maintain contact with Nicola del Roscio, giver and taker of access, but the enigmatic man flits in and out of the story like a white shark in dark waters. Near the end of their first periphrastic meeting, del Roscio asks Rivkin, “What is it you want from me?” A seemingly panicked Rivkin manages to say something brief and unmemorable, but as he speaks, his mind is spiraling: “Tell me about the ‘turmoil’ you felt after you first met him, or how it felt to shake Twombly’s hand … Tell me about the first time you talked when there was no one else there, how the rooms of Via Monserrato smelled. Tell me about grief. Tell me everything.”

But for every boyish burst from Rivkin, there are plenty of measured, keen observations. Nicola is “at once imperious and vulnerable … An island. A keep … Perhaps this was one of the things Twombly recognized in him … One wrong word, it seemed, might have ended the lunch.” And when an unexplained man joins their table: “Cue-ball bald, gold jewelry jostled on his wrist and neck. I didn’t catch his name or why he was there exactly, something about money.”

Perhaps the most important subject of this book is the desire to know others: the desire to know an artist who has unwittingly changed your life, or a person whose life seems to hold some secret about your own, or one’s lovers, or oneself. It’s also a long, haunted letter of unrequited love, and a meta-analysis of true biography’s impossibility. If the work is incomplete in reporting the truth of the artist’s life, it is because the Twombly Foundation wishes for it to be so. Yet it is a fitting thrill to end Chalk still wanting more. “Desire is not simple or safe. In life and in art, desire is the complication.” Desire, too, feeds on incompletion, on distance, on inscrutability. Chalk’s readers, just like Twombly’s devotees, will recognize the erotic pull within the omissions.

Catherine Lacey is the author of The Answers, Nobody is Ever Missing, and, most recently, Certain American States.