We are running against time in this car, but we still need to eat, so we stop at McDonald’s to get Egg McMuffins, and we quietly chew while I drive. We hardly speak, because what is there to say? Instead, we take turns using my mother’s new fingertip oxygen tester on each other, to test the amount of oxygen in our blood. I don’t know how it works, but it does. My mother tests herself first. Without oxygen pumping into her nose through a clear plastic tube, she only has 78 percent oxygen in her blood. This is bad. This is why we presume she is dying. The normal amount of oxygen in your blood should not dip below 88 percent. She asks my father for his fingertip and he produces it between our seats and she clicks the tester onto his finger and we wait. When his reading says 96 percent she feels like she’s lost something, a competition, but they have different ailments, so it’s hard to compare.

“Let’s test the healthy one,” my mother says.

“I’m driving,” I say.

“Just give me your finger.”

I do what she tells me to do, because she is my mother, and when my reading comes back 100 percent she says, “Do you see this? She’s perfect.”

But the problem is, I’m not, and I know it.

We whiz past exits and rest stops into the open desert, where there are whirling dust devils on either side of us. Some are small and some look like massive tornadoes of dirt. One crosses over the road we are driving on and I wait for something miraculous to happen, but it just disappears around us.

“We should be taking care of you, not the other way around,” my father says from the back seat. I take note but stay silent. He does this now: makes unprompted declarations laced with guilt.

Ahead I see the dark clouds of thunderstorms and watch as soundless lightning shoots down into the nearby hills. I know we are going to drive into the storm, and my mother is scared, but I tell her not to worry. When we reach the rain, it is torrential and I can’t see the yellow lanes anymore, but I can’t just announce that, so I keep quiet. My father is frozen in silence in the back seat, still staring out the window. Lightning strikes near his side of the car, but he doesn’t jump, he just opens his mouth in childlike awe. As we reach the edge of the clouds, I slow the windshield wipers and open the window to smell the rain on the hot asphalt.

From the back seat my father says, “Petrichor.”

“What?” my mother asks.

“That’s what this smell is called,” he says as the sun envelops us.