Early on in “Fever Dream,” Samanta Schweblin’s mesmerizing debut novel, a young mother tells a friend about a calculation she is forever making and remaking. She calls it the “rescue distance.”

(Riverhead)

“That’s what I’ve named the variable distance separating me from my daughter,” Amanda explains, as she watches her child tottering perilously toward a swimming pool.

But Amanda’s obsession with the rescue distance doesn’t ease her fears. It amplifies them. The more she measures, the shorter the distance becomes. She likens it to a rope, pulling ever tighter, tugging at her maternal preoccupations, tormenting her. “The rope is so taut now I feel it in my stomach,” Amanda says while struggling to explain her primal anxiety.

Amanda is a woozy chronicler of her demons, for she tells her story while lying on her deathbed, felled by some toxic, man-made menace. Her recollections are prompted, with growing urgency, by a friend’s child, David, who sits at her bedside and pushes her into an agonizing self-exploration, all the while reminding her that she soon will be gone.

David — Schweblin hints — might be a hallucination, a product of the fevered state that gives the novel, nimbly translated by Megan McDowell, its title. But his existence or nonexistence doesn’t really matter because the emotions he elicits are so chillingly real and familiar.

Schweblin, who was born in Argentina and lives in Germany, was hailed by Granta several years ago as one of the best young Spanish-language writers, and she has been lavishly praised by the likes of the Peruvian master Mario Vargas Llosa and the celebrated Colombian novelist Juan Gabriel Vásquez. “Fever Dream,” a slim novel that was originally published in Spanish in 2014 as “Distancia de Rescate,” represents a new phase in the career of Schweblin, 38, who had previously dazzled her literary admirers with collections of her deftly constructed short stories.

Like her characters, Schweblin has been taken by the notion of distance. In a BBC interview, she recalled how she befuddled her teachers by refusing to speak for a time at age 12 because she was frustrated by the distance between her thoughts and her ability to make others understand them.

In the hands of a less talented writer, “Fever Dream” might have veered into the realm of the predictably macabre. Amanda and her daughter are incapacitated by a mysterious substance leaching into the ground and the water at the countryside vacation spot where she and her family have sought respite from the grime of the city. Before long, horses and ducks and dogs are staggering around in wobbly death throes. Misshapen children appear in the gloom of remembrance. A house Amanda visits has a back yard-turned-burial ground, studded with piles of dirt.

Author Samanta Schweblin. (Alejandra Lopez)

David’s mother, Carla, remembers seeing him with his back turned, “small and strange with his arms hanging down by the sides of his body and his little fists clenched, as if he’d been startled by something threatening.”

Schweblin, though, is an artist of remarkable restraint, only dabbing on the atmospherics, while focusing her crystalline prose on the interior lives of the two mothers, Amanda and Carla, as well as the vagaries of memory.

David wants to control the conversation, to shape the contours of Amanda’s story. He is insistent. “The important thing already happened,” he chides at one point. “What follows are only consequences.”

But Amanda, like most of us, desires a measure of control over her own narrative. “It scares me when you don’t say anything for so long. Every time you could say something but don’t, I wonder if maybe I’m just talking to myself,” she says. “I want to know what’s happening now,” she demands, pushing forward through the muck of her past against David’s attempts to channel her thoughts.

Schweblin renders psychological trauma with such alacrity that the conceit of a poisoned environment feels almost beside the point. The requisite scene of workers unloading sinister barrels of chemicals is rendered quickly. It’s a mere steppingstone in a meatier drama, and one that we’ve seen produced in even more frightening and convincing fashion in nonfiction works, such as Jonathan Harr’s brilliant “A Civil Action” about an infamous water contamination case in Woburn, Mass.

Schweblin’s characters drink mate and eat dulce de leche doughnuts, but she doesn’t dwell on hallmarks of a geographical place. The space that she evokes most vividly lies between our rational minds and our preoccupations.

When Amanda arrives at the vacation home, she can’t sleep. “Before all else,” she says, “I have to know what is around the house. Whether there are dogs, and if they’re friendly, whether there are ditches, and how deep they are.”

Comfort is derived from controllable, manageable locales. David’s mother lives in a nearby home swaddled by wheat fields, a perimeter she appreciates “because it makes our yard smaller, more intimate.”

The protective urge consumes Amanda, and Schweblin pulls the rope closer and closer until the rescue distance is almost gone.

After reading “Fever Dream,” I wanted Schweblin to let the rope out more. Not because “Fever Dream” isn’t an almost perfect short novel — because it most certainly is. But because I wanted to see what Schweblin could do when she went deeper into the place where she so skillfully had taken me.

Fever Dream

By Samanta Schweblin

Translated from the Spanish by Megan McDowell

Riverhead. 183 pp. $25