There is a moment in the 2015 movie "Mr. Holmes" — the story of an aging Sherlock, played by Ian McKellen — when a young boy, played by Milo Parker, asks Holmes to do his thing. Holmes is confused. My thing? The thing where you deduce from a fingernail or the impression in a carpet that someone is guilty.

I love this moment because I had been waiting for it, too, that moment when something ineffable and true can be seen, can only be seen, from slantwise evidence.

So much of our lives are purloined letters, secrets in plain sight, yet there is one bit of evidence I find especially compelling. Stacked, sometimes even neatly, by a favorite chair or by the side of the bed, the to-read pile is a peculiar type of evidence: evidence of hope, and optimism and belief in grace.

At the moment, my to-read pile has six titles. Last week it had nine. Next week, if time allows, it will have five. But then I will add to it and the number will grow. With luck, that space on my floor will never be empty.

The to-read pile — and I don't mean the one with books we feel we must read or are assigned — is private ground. These are the books we let inside.

This afternoon, my list includes two by Jan Morris, Carolyn Forche, Barry Lopez, Paul Theroux, Ian Frazier. The demographics of the authors are accidental to this week as last week's list would have included Erica Dunbar, Annette Gordon-Reed — the list changes often.

I sometimes wonder if these people would get along as well in real life as they do in my head.

To be clear, though, I should say the list changes me. The fact that most of the titles are nonfiction tells you where my heart and mind work together, though fiction and poetry and especially collections of photography race through the stack.

These authors are opening the world for me, inviting me to see places and histories and ways of imagining I cannot yet, well, imagine.

A long time ago, I came to understand that every word and every idea is a gift. Not from some larger power to a storyteller. But from a writer to whatever reader the words may find. To give a gift is intentional. To give a gift is an act of respect and love.

The to-read pile is evidence of an accepted invitation, an accepted gift. Here, the authors say, I have a story for you.

What would Sherlock deduce? Or Poirot? Or Jessica Fletcher? Look close enough and the answer would be soul-core hope.

Because I know Carolyn Forche, I wrote and asked if she had ever met Barry Lopez or Jan Morris in real life. I needed to know. One of her books is between those two others by my chair.

"Yes," she said. "I met Barry in Alaska. We took a Zodiac into a cove to visit sea otters. I never met Jan, but I would like to have had."

The cove was a good trip? I asked.

"It was magical."

W. Scott Olsen is a writer and professor in Moorhead, Minn.