Lilia Liska doesn't care what you think of her. Or so she claims.

The elderly protagonist of Yiyun Li's stunning new novel, "Must I Go," takes pride in her toughness. "I'm as hard as the hardest life," she says, her heart tempered by the deaths of her three husbands, and the suicide of her daughter, Lucy, at age 27.

But as Lilia reflects on her life from her California retirement home, she shows signs of softness, of vulnerability, though if you blink, you might miss them. She's a fascinating character, filled with resentment and regret, but compelling enough that the reader is unable to look away.

"Must I Go" finds Lilia perusing the diaries of Roland Bouley, a Canadian writer with whom she had a series of encounters when she was a teenager and he was an adult. One of those led to the birth of Lucy, although Roland remained unaware of his daughter his whole life; Lilia raised her with her first husband.

Lilia doesn't talk too much with her remaining family, with the exception of Katherine, Lucy's daughter, and Katherine's daughter, Iola. When others in the retirement home urge her to join them in taking a memoir writing class, she resists: "If there was one thing Lilia had been unwilling to leave to her offspring, it was her own life story. … She never cared for her heart to be known."

She decides instead to annotate Roland's diaries for Katherine and Iola, so they'll be able to know the ancestor they never knew. And while she obsesses over Roland and the two loves of his life, she keeps coming back to her memories of Lucy, and the grief she can't escape. "Every morning since Lucy's death, I wake up and say to myself: Here's another day that Lucy refused to live. Not a day she gave up," Lilia writes. "All the more reason for me to live each day, to prove a point: I refuse to accept her refusal."

Li tackled the theme of losing a child to suicide in her last book, "Where Reasons End," and in her new book, she handles it with the same grace. Lilia steadfastly refuses to believe that she played any part in Lucy's depression, but when she lets her guard down, the reader can tell the prospect has crossed her mind: "I didn't understand her rage. … Was this a mother's failure? But how many mothers are not failures?"

Lilia is a true original, and Li wisely lets her speak for herself through the bulk of the book as she riffs on Roland's writing. Li does a wonderful job of letting readers decide how much of what Lilia says is true grit, and how much is the bravado of a proud but wounded woman. "Must I Go" is a triumph of a novel about how we navigate grief that seems unmanageable. "The days after love are long and empty," as Lilia declares. "It's up to you and me to make them less so."

Michael Schaub is a member of the board of the National Book Critics Circle. He lives in Texas.

Must I Go
By: Yiyun Li.
Publisher: Random House, 368 pages, $28.