I found the first one a week after the burial, inside his old toolbox in the shed. Next to it were detailed plans, down to the millimeter, for building the wall. The shaky handwriting of Guillermo, my dear retired meteorologist, read:

“My beloved Marga, if you are reading this, it means I am no longer here to protect our home. Build the wall according to the plans. It will seem like madness, I know, but trust me as you always have. Something big is coming.”

I kept working. The sun rose and warmed the stone, but I felt an inner cold that nothing could take away.

That same afternoon, Beatriz, Guillermo’s sister, appeared. She had always been a city woman: perfect ash blonde hair, designer handbag, the look of someone who considers the countryside a picturesque but uncomfortable place. At fifty-five, she never hid the fact that she thought I, a country girl, wasn’t good enough for her “intellectual” brother.

“Margarita, we need to talk. This has gotten out of hand. You’re the talk of the whole region,” he said without even saying hello.

We sat in the wicker chairs on the porch, facing the adobe and stone ranch that Guillermo had restored with his own hands forty years earlier. The property was in a high area, surrounded by pines and oaks, far from the town’s tourist center. It was our private paradise.

—Beatriz, you can’t continue with this obsession. Guillermo is dead. You have to accept it and move on. This whole wall thing is… grotesque.

“I accept that she died, Beatriz. I accept it every morning when I wake up and the bed is empty. But that doesn’t mean I’m going to ignore her last wishes.”

—What will, for God’s sake? You’re talking about a man who was very ill in his last months. The medication, the pain… perhaps he wasn’t thinking clearly when he wrote those supposed letters.

I felt a hot pang of anger in my chest.

“Guillermo had a weak heart, it’s true. But his mind was brilliant until his last breath. He was a meteorologist, Beatriz, and one of the best. He was always obsessed with weather patterns.”

—Yes, yes, I know. But in his later years he spent hours looking at old data and doing calculations that nobody understood. That’s not science, Marga, that’s senility.

“Respect your brother’s memory!” I snapped, getting up from my chair.

She sighed condescendingly.