One summer in San Francisco, studying in the city I would much later call home, the camera came with me everywhere.

It was there on my honeymoon in Thailand. It was there—now digital, now video—when Zoe was born. When she learned to ski, I mounted a camera on my own helmet and filmed her runs … watching the mountain unfold around her, fast and wide open.

Then the ski trips changed. In British Columbia, what we were told was optic neuritis. In Aspen, it looked like MS, ALS, Parkinson’s—motor skills degrading before our eyes, in real time—but the doctors there called it vertigo. The mountains were where her cancer first announced itself, disguised, one trip at a time. The camera kept rolling because it was what I knew how to do … but the habit faded when life demanded everything else, the way it always had. And it reappeared, the way it always did, when things got hard.

When my marriage ended, that was the season the sky found me.

A year before Zoe’s third bout, I met Heather … an epidemiologist before most people knew the term.