Varanasi, where I was born; Zurich, where we met; Tafilalet, my first lab posting after we got our doctorates, and the mouth of the Moulouya, where you yelled in my ear with incomprehensible joy at seeing an Audouin's gull. Alcântara, where we sat for weeks in a hospital for decontamination before they would let us fly back to the Academy on our return from the Ishtar Sink. We joked about their bad coffee and single-serve pudding cups for years afterwards.

Earth was a foreign country after Venus's swamps: startlingly harmless. Only we knew what it felt like to hold yourself in your own hands and let go. There was nothing that could hurt us on Earth except putting a hand on a hot stove—not like going too far without a rebreather, hazarding ourselves too carelessly in the laboratory, or unwisely taking citizenship with the North American Empire. It took time for us to remember how to be human amongst humans.

Decades of work following, sometimes apart, sometimes together. Then Hyperion for you and Lhasa for me, our two lonely mountains nine hundred million miles apart.

Lhasa, where I sat and looked into the future, and learned to fear what I saw.

Now the town is overgrown and wild, with shrubs crawling down from the mountains. White paint has flaked off brick, and dust has blown in.

The high paths here were hard for the Maya who was. Thin air, high slopes, short legs. She took it as a challenge the rare times she remembered the world outside of her lab.

There's no difficulty here for me. My body is perfect. Hydraulics in my fabricated knees take me up step by step, without effort, without sound. I summit the peaks as easy as slicing through a Vex gateway.

In my time, the labs sat on a rising slope away from the center of the town. Old models, new materials. Ultra-strong alloys, lightfast pigments. Concrete and rebar below the self-leveling floor compounds, no copper needed for the foundations.

Now, broken windows and leaves are strewn across the floor, empty fittings at the center of the labs. Scavenged remains stolen away to the last living city on Earth, Lakshmi's project built out of the ruins of my work.

She made a mess of things, my little alter ego. No sense of proportion. When I find my Chioma again we'll laugh. Look, I'll tell her. You have hundred twenty-seven false copies; I'm plagued by two hundred twenty-eight. You approach unity quicker than I! I always knew you were nearly perfect.

Time has ruined this valley: time and poor stewardship. No simulation, yet it feels false.

My heart, my happiness, my life—all locked away in another time. They could be mine again if I can make a trade.

An age for an age. Lead for gold: the alchemist's unrealized dream.

I walk towards a window. There's broken glass on the floor, but it does me no harm. Not now that I'm perfect.

Dry wind blows in my face, the dust it carries pulling at my clothes and sliding off my metal-and-ceramic skin. This body of mine doesn't cry, Chioma. A weakness I've lost and almost don't miss.

The wind doesn't smell the way it did when I wrote to you, my beloved.

But it will.