Blake told us about the killings when we returned from vacation.

As we pulled away from Denver International Airport’s glowing tent terminal, he said, "There was a shooting in Rifle. Four people got killed at the City Market. It looks like the guy was going after Mexicans." I glanced at Anjula, my wife. She stared straight through the windshield, apparently absorbed in the weave of red taillights ahead. Her skin, a rich nutty brown, was almost black in the car’s darkness. My friend Blake kept talking, sharing more bloody details, unaware of the anxiety ballooning in his car.

Anjula and I didn’t have to speak to know what the other was thinking. Our town wasn’t far from Rifle. We had a City Market of our own. Anjula had been mistaken for a Mexican before.

Anjula and I live on the Western Slope of the Rocky Mountains, in a place of sculpted mesas and sprawling farmland; a river valley patchwork of apple orchards, hay fields and browsing cattle. Pickup trucks wind along thin strips of pavement between the valley’s isolated towns. I grew up in this place. When I was little, I squatted in my family’s irrigation ditches and piled the land’s red mud onto my head. When I was older, I watched the juniper tree hills behind our house explode in 50-foot wildfire flames. I attended the high school where the highest math was trigonometry and where the Spanish teacher was really a wrestling coach in disguise.

This is a place I know well. I see it differently now.

Anjula and I lay awake in bed, clutched together. In another room, Blake was already blissfully asleep.

Anjula said, "I wish he hadn’t said anything about that shooting."

"I don’t think he knows how nervous it makes us. Maybe it’s his way of telling us to be careful."

It had that feel to it: A sort of weather report on ethnic violence. Sunny but colder today with highs in the 40s and four Mexicans dead outside the City Market. Bundle up.

"I hate hearing things like that," Anjula said.

"Yeah." There wasn’t much more to say.

Anjula said, "You’re doing the grocery shopping from now on."

We laughed quietly, a small secret laugh, wishing it was that simple.

We held each other in the darkness, wondering what had driven us to test the fine edge of racial tolerance in a place where dark-skinned people stand out with the clarity of bull’s-eyes.

Fine veins of Indian culture break the smooth polish of Anjula’s American surface, like biotite seaming through marble: the salty mango achar she snacks on; the aunties who call and invite us to weddings in India; the small shrine where she burns incense to elephant-headed Ganesha, the remover of obstacles, and Lakshmi, the goddess of wealth and prosperity.

But these aspects are invisible to outsiders. She seldom wears the red mark of a married woman, the bindi, on her forehead. She reserves her saris for visits to her family and to her celebration of Diwali, the Hindu festival of lights. In her daily life, she wears jeans and polar fleece and cooks pasta rather than palak paneer.

If not for her skin color, she might blend with any American community. And yet her skin remains, a stubborn thorn of diversity.

When Anjula and I moved to the valley, we knew that we were testing the unknown, entering a place where minorities were few. The valley’s population was not homogenous: Hippies, ranchers, telecommuters, coal miners and retirees all shared the place. But almost every one of them was white. Anjula’s first tour of my hometown left her uneasy, shaken by uniqueness. People were friendly, but they also seemed to watch her, the explicit stranger.

In town, she introduced herself as someone whose parents were from India, to ensure that no one confused her with the Utes who previously populated the land. She was an Indian — the dots, not the feathers — but more often than not, she was mistaken for a Mexican.

Migrant Mexican farmworkers support our agricultural economy and represent diversity, such as it is. They pick apples, peaches and cherries. They live shadow lives hidden from our eyes. We see Mexicans in the City Market: men in jeans and striped button-front work shirts, wearing cowboy hats or sometimes plastic mesh baseball caps. They shop and leave and we seldom see their homes or communities.

And then, all of a sudden, their shadow lives spring into focus and they are dead in a parking lot, and our own lives spring into focus as well.

Anjula and I went back to our regular lives, convincing ourselves that bad things happened in Rifle, but wouldn’t happen in our town. Still, I watched people differently when I was with her. I watched them as we walked down the sunny main street hand-in-hand, and when we entered a restaurant. I watched them as we waited at the cash register at the farm supply store.

We want to think the best of our neighbors, of the strangers on the street. We want the things we fear to be simply that: things we fear, which don’t exist. Like monsters under the bed, or ghosts in the closet. For the most part, our hopes are born out.

But always, always, Anjula and I are making calculations, guessing at our status in the place we live. It’s uncharitable and paranoid. It’s the worst of ourselves that we bring to this equation, the worst assumptions of the stranger who climbs out of his truck, or pushes her grocery cart into City Market. And yet, it’s part of our lives.

Last week in our town, a group of young white men dragged a Mexican man out of his car. They beat him, robbed him, and left him for dead. Other people trust. Other people live in this place and know that they are safe. We live here and treasure the good days, estimate our safety on the bad days, and hope that we never make a mistake in our calculations.

Paolo Bacigalupi lives in Western Colorado.