Atticus Lish’s new novel, The War for Gloria, is among the bleakest books in recent memory.

Set around Greater Boston, it follows a high-school student named Corey Goltz, who’s been thrust into the role of caretaker for his ailing mother as she progresses toward quadriplegic paralysis from A.L.S. Things turn violent when Corey’s estranged father, an abusive psychopath named Leonard, returns to take advantage of his debilitated ex. Part unflinching study of degenerative illness and part thriller, the book reads like something Denis Johnson might have written had he binge-watched all those Affleck-brothers movies about Massachusetts townies.

But Lish himself does not appear to be the brooding type. The 49-year-old ex-Marine is clean-shaven and boyishly handsome, with bright-blue eyes that are often obscured by fluttering eyelids. He offers an easy smile as he recounts the four months he spent sleeping in a moving company’s storage warehouse in Concord, Massachusetts, while researching the novel. He was there for so long that he earned the nickname of “warehouse cat.”

In a literary scene populated by M.F.A. clones, Lish is an anomaly. He is the son of Gordon Lish, the Esquire fiction editor turned book editor known for both his radical excisions on Raymond Carver’s early short stories and his tyrannical teaching style in the private writing workshops he ran for years. But Atticus, not unlike the protagonist of The War for Gloria, spent large chunks of his life estranged from his father and cut his own path.

After attending prep school at Phillips Academy, in Andover, Massachusetts, he matriculated at Harvard, only to drop out after his sophomore year. From there he worked a series of low-wage jobs before enlisting in the Marines. He moved back to Massachusetts when he left the service, in 1996, and began training as a mixed-martial-arts fighter. This took him to California for a spell, though he eventually returned East to finish his degree.

“I wanted to make some money,” Lish explains. Instead, he wrote a novel.

He matriculated at Harvard, only to drop out after his sophomore year. From there he worked a series of low-wage jobs before enlisting in the Marines.

Rather than share it with his father, a longtime Knopf editor, Lish chose to publish Preparation for the Next Life with Tyrant Books, a small press run by a friend. The book, which came out in 2014, was an unexpected success, winning the PEN/Faulkner Award.

“I asked myself, What is the nerve in your tooth?,” Lish says, when asked about the genesis of his second novel. “If you feel around, what hurts?”

Lish’s father, Gordon, a former fiction editor for Esquire and longtime editor at Knopf. The two were estranged from each other for 12 years, a feud echoed in Lish’s new novel, The War for Gloria.

The answer was his mother, who died when Lish was 15 after her own excruciating struggle with A.L.S. The War for Gloria—out next month from Knopf—is, in large part, Lish’s reckoning with both his mother’s illness and its effect on his teenage self.

I asked if it was painful to revisit this period of his life. “I didn’t enjoy thinking about it,” he says, before going on to recall, in detail, watching his mother spasm from choking while a machine cleared fluid from her throat.

The circumstances surrounding her death complicated things further. “Because I was in a feud—because the son was in a feud with the father—my mother died alone,” he says. “I got kicked out of the hospital, and it was related to that. So that will forever be on my conscience.”

I noted his strange drift into the third person, a momentary blurring of the boundary between fiction and life. Lish is cagey on the details of exactly what went down between him and Gordon, but I know they didn’t speak for 12 years after his mother’s death. While there may be autobiographical aspects to the novel, however, I’m reticent to read too much into the book’s depiction of Leonard as a crazed killer. Still, I couldn’t help wondering what Lish thinks about his own father these days.

“I’m alone in the ocean. It’s night, and there are sharks in the water,” he replied, adding, somewhat less cryptically, “This is life. You’re gonna die. He’s gonna die, too.”

While he doesn’t sound as chipper as he did when we first started talking, he doesn’t sound agitated either. I sense that whatever anger may have animated him in the past has been let go.

“He’s not a father to me anymore,” Lish says. “He’s another man who has to die. I’m another man who has to die. I think it’s my age maybe, you know? I don’t hold anything against him anymore.”

Adam Wilson is the author of Sensation Machines