In her 10th and latest novel, Ellen Cooney has created a small wonder of a book with its mix of everyday life, mystical longing and practical truth. “One Night Two Souls Went Walking” informs readers, right from the top, that we’re leaving the material world for something less earthbound. And yet, thanks to her storytelling skill, Cooney easily straddles the line where those two spheres co-exist.

Welcome to the night shift, where the narrator, an unnamed chaplain in her 30s, is making her rounds at the medical center. We meet a cast of motley characters, some of whom have asked for the chaplain; others are less receptive to her visit. Among them are a lawyer and a baggage handler; a bank teller who worries that the angel she sees is too slight to carry her body off; and a teenage surfer, brain-damaged in a fall, who believes that waves are holy.

In conversation, the surfer allows that the chaplain reminds him of Annie from the eponymous musical.

“Did I know what he meant, that dumb movie, but the orphan girl was kind of all right?

“I knew what he meant, yes, thanks a lot for putting that song in my head,” Cooney writes.

We watch the chaplain at work, ministering to victims after a roof collapses at a nearby store, and consulting with doctors and staff at the hospital. In one case, a young doc admits that she couldn’t bring herself to respond to a skiing accident while on vacation. Instead, she got in her car and went shopping. Later, she questions whether she might have saved a life, and how to forgive herself.

Ever a sounding board, the chaplain listens and consoles. She judges only the type of relief that’s needed. And if lying is called for, then lie she will.

“ ‘I believe in expecting light,’ I say, as if it doesn’t matter they can only be words to hang on to, out of habit, when there are no other words, when I am looking at darkness,” the chaplain says.

As it happens, the chaplain herself is a bit of a mess in ways that are wholly endearing. A frizzy-haired “human dumpling,” as her older sister dubs her, the chaplain is self-effacing and droll, awkward in the face of dying patients, and prone to fleeing from social situations. And she’s had a couple of rocky romances that have left her pining and unsteady. Her work with troubled and dying souls proves therapeutic for her own broken self.

“I have never told anyone I love this place as if it were a person,” she says.

At the heart of this gently searching novel, Cooney, who lives in midcoast Maine, poses a large existential question: What is a soul? Cooney presents a series of vignettes, of deathbed vigils and confessions of the living, that suggest a range of possible answers. Factor in a late beloved therapy dog who used to join the chaplain on rounds, and a successor dog, who may be a phantom or a ghost, and the author has her work cut out for her.

With its evocation of souls and ghosts, this book might well have derailed into queasy terrain. Yet Cooney manages to pull off this balancing act with more than a modicum of humor and charm.

Her secret weapon, of course, is the chaplain whose warm no-nonsense demeanor and chronic self-doubt keep the book honest, even when her musings run wild. Her three-dimensionality is key to her appeal, giving the book both its wings and its feet on the ground.

“One Night Two Souls Went Walking” is as winsome and eloquent as its title suggests. In the end, it’s a book about empathy and hope that floats big questions and has the grace to leave them largely unanswered.

Joan Silverman writes op-eds, essays and book reviews. Her work has appeared in numerous publications including The Christian Science Monitor, Chicago Tribune and Dallas Morning News. She is the author of “Someday This Will Fit,” a collection of linked essays.