“A whole pool of it,” he said. “There’s a natural spring up that hill.”

He showed us where he meant: a scrubby slope rising away from the highway, pinned in place by a few gnarled trees. The ocean felt a thousand miles away rather than a hundred; it was just a notion somebody had had one day in the middle of the sand, an impossible act of imagination.

We followed dirt switchbacks to the pools: a tub of murky water breathing curls of steam, circled by fake rocks. Tilly took off her shirt and then shimmied out of her denim skirt. Her bra was the color of an old photograph, that sepia, and it barely kept her long breasts from swinging out. She tap-danced across the concrete. “It’s like a stove!” she said. “You’ll burn your toes!”

She was right about the ground. But the water was hotter. We held our bodies perfectly still under its surface. Even the smallest movement made tiny unbearable currents, like boiling threads, against our skin. Tilly gritted her teeth. “I’m barely here,” she said. “I think I melted.”

The hill behind her was covered in cacti, their broad paddles studded with needles that stuck like pins into the rippling warmth over the land.

Tilly dunked her head under. “All I wanted was a little peace from the heat,” she said. “This state is just as bad as the last one.”

She took the curves of Highway 1 with a grim face, slowing for each long bank around the cliffs, but sometimes we got a view, wide and rustling blue, and I could see her faintly smiling. We were tired. We watched the fog burn away. The land was full of dingy, infinite mysteries. The roads were lined with produce shacks. There was an island barely bigger than a shopping mall, tethered to the coast by a thin bridge whose distant dirt heaved flickering oil flames against the blue sky. We passed broad hills that rolled steady and seemed to die a little in the furrows, their grass baked brown like too much sun had pooled there. We saw a whole flock of blackbirds rise from the land and make a shape in the sky, wing to wing, that was larger than any of them would have been able to imagine. “How do they know what to do?” Tilly asked. “I never get that.”

We didn’t stop much. There was one time we saw dolphins, another time we bought pistachios. Mostly, we listened to folk music and tried to keep our truck steady on the curves. Tilly wanted to make sure I hadn’t told my mother about her work. I hadn’t.

“Good,” she said. “Like I said, she wouldn’t get it.”