FICTION: "This is How You Lose Her," by Junot Diaz.

Junot Díaz writes with subtle and sharp brilliance. In these nine short stories surrounding the troubles and travails of relationships, sex and love, Díaz dazzles us with his language skills and his story-making talents, bringing us a narrative that is starkly vernacular and sophisticated, stylistically complex and direct.

The stories in "This Is How You Lose Her" revolve around Yunior, the character and voice who narrated Díaz's Pulitzer Prize-winning novel, "The Brief Wondrous Life of Oscar Wao," and who appeared in Díaz's first story collection, "Drown" and -- as it turns out -- is the nickname of Díaz himself.

Here we learn of Yunior's family, who left the Dominican Republic for New Jersey: his brother, Rafa; his Mami and mostly absent Papi. Above all else, it seems, we learn of Yunior's many infidelities. He gets in trouble with the ladies all the time, as in the collection's opening story, "The Sun, the Moon, the Stars," where he tells us about his chica, Magdalena, whom he finally realized was particularly special to him, but not before he cheated on her with Casandra, who sent Magda a letter telling all. Things did not turn out well for Yunior.

Throughout this collection, Díaz creates a fascinating dynamic for the reader, revealing Yunior's life as a young man (and as a boy) where we are, at times, repelled by his insensitivity to women but sympathetic to his charm and his plentiful moments of compassion.

Díaz develops characters with stunning virtuosity. In "The Pura Principle," Rafa is dying of cancer and Yunior relates the difficulties of taking care of him; he tells us: "I was seventeen and a half, smoking so much bud that if I remembered an hour from any of those days it would have been a lot." And how his mother dealt with this crisis: "She'd never been big on church before, but as soon as we landed on cancer planet she went so over-the-top Jesu-christo that I think she would have nailed herself to a cross if she'd had one handy."

And Rafa: he "prided himself on being the neighborhood lunatic, wasn't going to let a little thing like cancer get in the way of his official duties."

With beautiful descriptions ("She can still smile ... so brightly it is a wonder that she doesn't set something alight"), simple spot-on declarations ("The day is the color of pigeons") and memorable characters, Junot Díaz's new collection blurs the line between fiction and memoir, creating a spectacular read.

Jim Carmin is a National Books Critic Circle member who lives in Portland, Ore.