For most people, chemotherapy is no longer the chamber of horrors we often conceive it to be. Yes, it is an ordeal for some people, but it wasn't for me, nor for most of the patients I got to know during my four months of periodic visits to the chemo suite.

But that Franklin trip changed me profoundly. As I believe wilderness experience changes everyone. Because it puts us in our place. The human place, which our species inhabited for most of its evolutionary life. That place that shaped our psyches and made us who we are. The place where nature is big and we are small.

The thing that most attracts me to historical fiction is taking the factual record as far as it is known, using that as scaffolding, and then letting imagination build the structure that fills in those things we can never find out for sure.

Both my parents loved words. That was the big deal in our house.

And at this moment in history, our core value happens to be the raw, aching truth of the human predicament. It may also be the only belief that can save us as a species. A species that will continue to find comfort and delight in the companionship of animals, the miracle of birds, the colours of the corals and the majesty of the forests. We are in it together, on this blue spinning marble in the cold and silent void. And we must act on that belief, if we are going to be able to continue to live a good life here, in this beautiful and fragile country, on this lovely planet, our only home.

I borrowed his brightness and used it to see my way, and then gradually, from the habit of looking at the world as he illuminated it, the light in my own mind rekindled.

When you're writing non-fiction, you go as far as you can go, and then ethically you have to stop. You can't go. You can't suppose. You can't imagine. And I think there's something in human nature that wants to finish the story.