On his deathbed, French botanist Michel Adanson repeats the word "Maram" over and over to his daughter Aglaé. The Wolof woman to whom the name belongs is a larger-than-life character in French-Senegalese writer David Diop's novel "Beyond the Door of No Return," inspired by Adanson's life.

She calls to mind another of Diop's outsized creations: the deranged Senegalese soldier in his slim, gory first novel, "At Night All Blood Is Black," which won the International Booker Prize. Think of a character who feels deeply wronged and harbors a personal stake in acts of retribution. And yet, as much as "Beyond" is written for and about the wondrously witchy and avenging Maram, it is not her story to tell. For better or worse, it is Michel Adanson's.

After Adanson's death, Aglaé discovers a dark-red leather portfolio in a hidden drawer. Inside are Adanson's notebooks from the years he spent in Senegal, West Africa, as a young man on a mission to discover and document plants. These personal notes, with whiffs of sentiment and dollops of sagacity, constitute the bulk of Diop's novel, giving it a confessional bent that leans on Senegalese cultural practices and history from the 18th century. (There's a lot of telling.)

The older Adanson, it turns out, has plenty to get off his chest about his misadventures in Senegal. They took place in a feverishly dark and turbulent time when French and English colonial forces vied not only for territorial power but also for slaves, many of whom were captured and sold by their own people into the transatlantic slave trade.

In the village of Sor, Adanson hears the captivating story of Maram, the chief's beautiful niece, who disappeared while out in the bush. Convinced she was taken by slave traders, never to return, the king and his villagers mourned her as dead. But one day, a man brings news that Maram is alive in a village near Gorée, the notorious slave-holding island.

Moved by Maram's story, Adanson sets out on foot with a small entourage, including a clever Senegalese boy named Ndiak, to find her. The ensuing journey, which involves spying, sickness and snakes, is one for the books.

After a slow start, mostly with Aglaé outside of Paris, the novel is propelled forward with the entrance of Maram, whose account of her disappearance, peppered with fantastical references to the spiritual world, is different from her uncle's. Wronged by men, she plans a spectacular act of revenge that Adanson witnesses and recounts in his notebooks, also charting his sudden love (or lust?) for Maram.

A professor with obvious knowledge of 18th-century Senegal, Diop has turned fascinating historical records into fiction in "Beyond the Door of No Return," aptly translated from French by Sam Taylor (it has been longlisted for the National Book Award prize for translated fiction). The results are invariably mixed, in part because of Diop's rendering of Maram as the tragic, foreign object of Adanson's sudden, blinding love, which could be more convincing.

Nonetheless, even 300 years later, Maram's touching story offers crucial lessons about unconscionable acts of slavery, perpetrated on both sides of the Atlantic Ocean.

Angela Ajayi is a Minneapolis-based critic and writer.

Beyond the Door of No Return

By: David Diop, translated by Sam Taylor.

Publisher: Farrar, Straus & Giroux, 243 pages, $27.