“The Risk of Us,” (Houghton Mifflin Harcourt) by Rachel Howard

With breathtaking brevity, Rachel Howard’s debut novel, “The Risk of Us,” illuminates the joys, challenges, fears and frustrations of adopting a foster child. And while she delves into the minutiae of “the system” and the differences of opinion about parenting styles, her deceptively thin volume is about much more than plunging into parenthood.

Howard masterfully illuminates how parenthood manages to bend even the most solid of marriages and expose insecurities about past relationships, including those from childhood.

In “The Risk of Us,” the unnamed narrator and her husband, Sebastian, choose 7-year-old, Maresa, “a brown-haired gremlin with arms flung like she could fly off the page” from a binder labeled “Children Available.” They spend the next year learning about Maresa, themselves and each other as well as the clearly dysfunctional foster care system in California.

Howard’s first book was a memoir, which isn’t surprising given the pages of her novel brim with emotion and vulnerability. She and her husband also are the adoptive parents of a former foster child.

Howard’s writing has a unique rhythm that feels choppy, even disjointed at first, but as the reader adjusts, her phrasing and word choices make each page sing. Not a single word is wasted here. There’s no bloat. Her writing is spare and elegant, yet it beautifully conveys intensity and emotional depth.

When the narrator comforts her husband: “My lamb. Salty wet face, closed eyes. Writhing side to side. . And then his chest is heaving against my cheek, and the sound we are making is called a sob.”

When Maresa throws a tantrum: “I am not baffled by this screaming girl, but my comprehension is no help. She is retching, she is shaking, she is spitting up bile.”

The only misstep comes near the end of the novel after what’s called “the day of the policeman” and the parents reconsider adopting Maresa.

But it’s a small lapse in a simply gorgeous novel.