“On the Calculation of Volume,” an ongoing seven-part novel by the Danish writer Solvej Balle, is the story of a single day in the life of its protagonist, the antiquarian book dealer Tara Selter, except that the day in question – Nov. 18 – repeats itself endlessly, each morning outwardly identical to the one before it. At the outset of the first book, Tara has already lived 121 Nov. 18ths; by the end of the second book, she has lived well over 1,000. “How had the damage occurred?” she wonders. “Where was the rift in time? What had I done on the day when time fell apart? Was someone to blame? Had someone made a mistake, and if so what?”

On the Calculation of Volume, I and II. By Solvej Balle, translated from Danish by Barbara J. Haveland. New Directions. Each volume $15.95, paperback

If Samuel Beckett had written “Groundhog Day,” it might read something like “On the Calculation of Volume.” The first volume unfolds like an existential mystery, a temporal whodunit. We learn that on Nov. 17, Tara left the home she shares with her husband and business partner, Thomas, in a fictional town in northern France. She traveled to Bordeaux, where she attended an annual auction of illustrated 18th-century books, before doubling back to Paris, where she stayed the night at a hotel. The first Nov. 18 she spent visiting antiquarian book shops, including one owned by a friend with whom she had dinner later that evening. She returned to her hotel, called Thomas and went to sleep.

On the morning of what she assumes is Nov. 19, she goes down for breakfast and is puzzled to see yesterday’s newspaper laid out by the buffet. But it is not until she sees a hotel guest drop a piece of bread and slowly pick it back up that Tara realizes something is amiss: “The moment I saw this hesitant action I knew that I was witnessing a repetition. I didn’t know that there would be yet another eighteenth of November the next day and then another and another, but I knew that something was wrong.”

Over time, Nov. 18 becomes not a day so much as a space to be explored, one whose depth and details are knowable, searchable. “I know how the day goes,” Tara writes. “I know its sounds and the intervals between the sounds. I know the shifts in the light and the intensity of the rain.” Returning home, she tries to enlist her husband in her attempts to figure out what has happened to her; together, they explore and observe, discover inconsistencies and anomalies, but no coherent pattern or mechanism emerges. Gradually, the toll of Tara’s having to apprise Thomas of her condition anew each day, even as she goes on accumulating Nov. 18s, becomes too great. After 108 days, she retreats to the guest room, where she lives unnoticed by Thomas. Eventually she quits their home altogether.

Balle, 62, first rose to literary prominence in her country in 1993 with “According to the Law,” a collection of four linked stories widely regarded as a central achievement of Danish fiction that decade. A few minor works, mostly collections of short prose, followed and then – nothing. The sudden appearance of the first installment of “On the Calculation of Volume,” in 2020, was heralded not only as a long-hoped-for literary comeback but an unlikely publishing phenomenon: The butter-yellow paperback, with its French flaps, published by Balle herself, divulged no information about the novel or its author. Balle had no editor, no marketing campaign and only a credit card for a safety net.

She needed nothing more: The novel’s individual volumes, five of which have appeared in Danish so far, have proved an astonishing success. In 2022, following the publication of the third book, Balle was awarded the Nordic Council Literary Prize, Scandinavia’s highest literary honor. The English translation of the first volume, marvelously done by Barbara J. Haveland, was nominated for a National Book Award. When I looked in at my local bookstore in Copenhagen recently, the third, fourth and fifth volumes were sold out. “I can’t recall anything like it,” the owner told me.

Written in intermittent diary-like entries of varying length, “On the Calculation of Volume” is at once scrupulously realistic and intriguingly speculative. Balle succeeds in conveying the texture of Tara’s changing feelings, her shifting moods. There are moments of crisis and accident interspersed with bursts of enthusiasm and even, at times, hope. In the second volume, as she travels north and south through Europe in search of seasonal weather – winter in Finland, summer in Spain – Tara is acclimatizing to her futureless condition when, suddenly, a Roman coin she has been carrying with her since Paris inspires an intensive exploration of the Roman Empire. Her research confronts her with the problem of consumption: If, as she learns, the empire’s downfall can be explained in part by dwindling resources, what of her own situation? She has already noticed that whatever groceries she buys are not returned to the supermarket’s shelves the next day. “I am a monster and I devour my world,” she thinks.

There are flashes of allegorical designs here, but in the main the novel’s propulsive imaginative brilliance lies in Tara’s metaphoric search for a language with which to communicate the sheer incomprehensibility of her condition. Her days are compared to a beach, a stream, a puzzle, a construction, a container. “I haven’t found a way out of the eighteenth of November,” she laments at the end of the second volume. As readers, we are only beginning to figure out how to navigate this beguiling, haunting novel, wherever it ends up taking us.

Morten Hoi Jensen is a Danish American writer. His second book, “The Master of Contradictions: Thomas Mann and the Making of ‘The Magic Mountain,’” will be published next year.