“I used to believe a person could teach herself to be merciful if she tried hard enough to walk in somebody else’s shoes, if she was willing to do the hard work of imagining the heart and mind of a thief, say, or a murderer, or a man who drove a fourteen-year-old out into the oil patch and spent the night raping her.”

So thought Mary Rose Whitehead, the 26-year-old Odessa ranch wife who answers her door the morning after Valentine’s Day, 1976, to find a girl named Gloria Ramirez on her front porch, only half alive, crying for her mother. If what Dale Strickland did to Gloria defeats Mary Rose’s notion of compassionate empathy, the reaction of her fellow citizens to the crime will just about wipe out her faith in humanity altogether. Once the justice system finally makes its pale contribution to the situation, we will have a vigilante on our hands.

“Valentine,” Elizabeth Wetmore’s fierce and brilliant debut novel, is set in Odessa, a rough-edged West Texas town built on cattle and oil. It evokes the physicality of the place with a visceral power that recalls Cormac McCarthy, and sets out its cultural ambience and mores with the ironic clarity of Larry McMurtry. This literary landscape has been defined by men as surely as the reality it represents. Wetmore sweeps them to the sidelines, defiantly and confidently claiming West Texas for the women and girls.

In the aftermath of the rape, the very pregnant Mary Ruth is no longer comfortable living out on the ranch. She rarely sees her husband anyway as their failing cattle business absorbs his every waking minute. She packs up her 9-year-old daughter and moves into town, right across the street from a retired English teacher and poetry lover named Corinne Shepard. “If you really want to know, Corinne would gladly explain to anybody who cared to ask, [she is] not a drunk, [she’s] just drinking all the time. There is a world of difference between the two.”

Corinne’s husband, Potter, is one of a handful of detailed and sympathetic male characters in the book, and he’s been dead for a year and lives only in Corinne’s mind. Wetmore’s portrait of Corinne’s grief is so vivid, so sad and funny and real, it could carry the book on its own. It is paralleled by the equal grief of another neighbor, Debra Ann Pierce, age 10, whose mother has recently left town with no forwarding address.

D.A. is a Scout Finch if there ever was one, and Wetmore gives her a perfect Boo Radley. Jesse Belden is a Vietnam vet from Tennessee who’s living in a drainpipe while he tries to earn enough money in the oil field to buy back his truck from his cousin. D.A. steals him food and supplies and tells him the stories she reads in books, since she’s pretty sure he can’t read himself. Every book has at least one good thing, she assures him.

Some have too many to count. “Valentine” joins the best Texas novels ever written.

 Marion Winik is a writer and professor in Baltimore and author of “The Big Book of the Dead.”

Valentine
By: Elizabeth Wetmore.
Publisher: Harper, 320 pages, $26.99.