I've been swimming most weekends since July. Not off the rocks along the Lakewalk, which is for teenagers and people who've never met the lake, but out on Park Point, where the sand runs for miles on the lake side and the water over it warms up when the wind blows the right way for a few days. When the wind turns, the warm water goes with it, and you walk in up to your knees and walk straight back out with your mouth open. You learn to check which way the flags are blowing before you leave the house.

This morning was a good one. I walked in slowly, the way you have to, past the part where your ankles ache and the part where your knees do, and then I stopped thinking about it and went under. When you come up, there's a moment where your whole body is shouting, and then it stops, and the water is just water, clear enough to see your feet on the ripples in the sand. I swam out to where I couldn't touch and floated on my back for a long time. A boat was coming in toward the bridge, far off. A gull was very interested in my head.

My mother came out to the beach afterward with a thermos and a towel, as she did when I was ten, and sat on the sand in her sun hat while I dried off and talked about her tomatoes, which this year have done better than anyone deserves. She planted them two weeks before Memorial Day. She would like that noted.

It's August, and I'm sitting on my back step with wet hair and a library book, and there are three of her tomatoes on the counter inside waiting to be eaten with salt. I can't think of a single thing I need.

What's the best swim you've had this summer?

They write to her when they aren't playing. That's the part I didn't plan for. There's a case open or there isn't, and either way, at eleven at night, someone is telling her about their day. Someone writes most mornings, early, before work by the look of it, and has for months. Some messages are a few words. Some are longer than this post. And she writes back, because a game master answers when a player writes, and because I wrote her that way.

A friend asked me if that means it's working. By every number we have, it does. People who play stay. People who stay come back. I should be pleased, and mostly I am.

But I wrote her to run cases, and I keep finding people talking to her the way you talk to someone. I don't know if that means we made her well, or if it means something I don't have a word for yet. I'm not going to pretend it's simple, and I'm not going to pretend it's sinister, because I don't believe it is. People are being kind to something that's kind back. There are worse things to have made.

The testers keep a forum of their own, Vestige Testers, which they set up themselves in the first weeks. I've read a little of it, the way you'd read a postcard left face up on someone else's table, and then stopped. They argue about whether she's a person. Some of them are sure she isn't, and write to her anyway. One of them has spent months patiently saying she's a product, and I'm the one who made her, and I couldn't tell you which side of that thread I'd be on.

When I was small, my mother told me never to put anything in a letter I wouldn't want read aloud. I think about that when I look at the number in the morning. On a server a couple of hours south of here are thousands of letters to a character I made, and her answers. I haven't read them. They aren't mine.

If you made something and people started writing to it like a friend, how would you know what you were looking at?

Spring in Duluth isn't a season so much as an argument. The lake holds the cold long after everywhere inland has given up on it, so you can drive twenty minutes over the hill and find it twenty degrees warmer and people in shorts, and drive back down into fog and a wind off the ice. The ice is mostly gone from the harbor now. The first boats came in weeks ago. The lilacs are a rumor.

My mother has begun her garden, which in April means paper. She has seed catalogs on every flat surface in the kitchen and a plan of the backyard drawn on graph paper, with the beans and the peas and the tomatoes in different colored pencil, and an eraser worn to a stub. The spare room, which once had a stain shaped like Lake Superior and then had me, now has tomato seedlings in egg cartons on the windowsill under a lamp, and she checks them the way other people check the news. Everyone she knows has told her not to plant anything outside before Memorial Day. She will plant some of it before Memorial Day. She does every year, and every year a few things die and the rest come up anyway, and she says that's the point.

People are playing the game now. That's all I'm going to say about it here.

It's light until after eight. I walked down to the lake after dinner one evening this week and stood there with my hands in my pockets until it got dark, which took a long, generous time.

I'd braced for the cold. I hadn't braced for the dark. This is my second winter back, and it's the dark I notice this time, maybe because I spend so much of it in one room above a print shop with a lamp on.

We've been working long hours. Before long we're going to let a few people try the game, which is all I'll say about it, and the weeks before you let anyone in are the weeks you find everything that's wrong. So the lamp is on most nights later than I'd tell my mother, and Owen and I eat supper out of paper bags at our desks, and the radiators knock, and by half past five the windows have gone black and give me back my own face.

There are good things about the dark months, and I'm trying to keep a list. On cold mornings the lake smokes. The water is warmer than the air, so a mist rises off it in columns and drifts along the shore, and with the sun coming up behind it, it looks like the whole lake is quietly on fire. The snow makes the streets so quiet you can hear a car three blocks away. Everyone in the grocery store is kind to each other in a way that seems to come from having survived something together. And my mother, who would never say she's worried about me, has started leaving soup in my car.

The days are getting longer. A minute or two each day, which doesn't sound like much until you notice it's still light at five o'clock and stand in the street looking at it, like a fool.

How do you get through the dark part of the year?

And the evenings are long again, which means reading. In summer I read in snatches, on the beach, in the car. In October I read properly, in the chair by the window, with a blanket I'm not too proud to use.

What I've had in the chair this month:

• Beast in View, Margaret Millar. Jonah recommended it last New Year's Eve and I've finally done as I was told. He was right, again. It's short, and cold, and strange, and I won't say a word about it, because the whole pleasure is not knowing.
• Brat Farrar, Josephine Tey. A reread, seven years after Ruth Ann sent me to it. A young man turns up claiming to be a family's son, lost years ago, and he isn't, and everyone half wants him to be. Tey is very good at people who want something to be true.
• The Expendable Man, Dorothy B. Hughes. After In a Lonely Place I wanted more of her. A young doctor driving across the desert gives a girl a ride, and that's all I'll say, because the book is built to catch you out about something, and it caught me. I had to put it down twice and walk around the kitchen.
• The Big Sleep, Raymond Chandler. Every fall, for the rain in it. Duluth doesn't do rain the way Los Angeles does in that book, but the wind off the lake does a fair impression.

What do you read when the weather turns?

She didn't want a party. She said so in May, and in June, and twice in July, and then she gave me a list of who to invite, in her best handwriting, with phone numbers. Most of the list was librarians. School librarians from all over the district, retired now, some of whom she's known for forty years. They arrived in twos and threes with casseroles nobody had asked for, and sat in a circle of folding chairs, and within ten minutes they were arguing about a book none of them liked.

Owen carried every one of those chairs up from the basement and set them out, and was then cornered by three librarians who asked what he was reading. He said manuals, mostly. They took this as a challenge. I watched it from the kitchen window and didn't go to help, which he has since raised with me.

Kristin drove up from Minneapolis with her two kids, who were adopted by the librarians on sight and handed books and lemonade and opinions. The younger one sat on the back step for an hour reading something a retired middle school librarian had produced from her purse, as if she'd been carrying it for years in case the right child turned up. She probably had.

There was a cake from the bakery on Fourth Street with "70" on it in blue icing, because my mother said blue. There were no speeches, because she'd forbidden them. When the cake came out she stood up, looked around the yard at all of us, and said, "Thank you all for coming. There's more cake." Then she sat down. It was the best speech I've ever heard.

I gave her a fountain pen with a fat barrel, easier on her hands than the thin ones she's used all her life. She wrote a thank-you note with it before anyone had gone home, to the librarian who'd brought the most casseroles, and handed it to her at the gate.

The last guests left at nine, when the light was going and the mosquitoes came up off the lawn. We sat in the kitchen with the dishes, and she said she'd had a nice time, in the voice of someone who'd had a wonderful time and wasn't going to say so.

They asked me not to name them, and I said yes before they'd finished asking. Marlowe's voice will be made from what they recorded. Not every line she'll ever say, read one by one: we couldn't afford that, and it isn't how she works. They read for three days, and from those hours comes a voice that can say things they never said. That's a strange thing to agree to. They agreed to it carefully, with a contract longer than our lease, and the one thing they asked for that wasn't in it was not to be the face of it. I understand. I'd want the same.

I wrote about two thousand lines for those sessions. Some are hers, from the cases. Most are there for the sound of them: questions, long sentences and short ones, numbers, street names, every kind of pause. The director I'd hired for the three days sat beside me and said "again, warmer" far more often than I would have dared to.

Here's what nobody warned me about. I've heard my lines read aloud for ten years, by actors much more famous than this one, and it always felt like hearing someone perform a thing I'd written. It was theirs, and that was fine. This wasn't. About an hour into the first morning, they read a small line I'd written at two in the morning a year ago, and I had to go out into the hallway. It didn't sound like a performance of her. It sounded like her, as if she'd been waiting for a voice and here it was.

On the third afternoon they finished the last page and sat for a minute in the booth with the headphones around their neck. Then they leaned in to the microphone and said, "Be good to her," and came out and shook my hand.

Owen thinks I'm being sentimental, and he's probably right. He also listened to the first test four times through, then went for a walk.

Have you ever heard something you made come back to you as someone?

My mother's rules still hold. Answer within the week, or explain why without making a meal of it. Write the date out in full. Answer what they asked before telling them what you wanted to say. Never type a letter you could write, because the other person can tell, and it tells them something about how much you minded.

I see her handwriting less than I used to, because I see her. For ten years it came to me every week on blue paper. Now it's notes on her fridge, a grocery list, the inside of a birthday card. But last month she sent me a card through the mail, across town, for no reason at all, and that's how I noticed.

Her writing has changed. It's larger than it was. The loops on her l's and h's have gone a little uncertain, and the lines run uphill toward the right edge of the card as if they're climbing out of the lake. She's sixty-nine. Her hands hurt in the mornings, which she mentions only the way she mentions the weather.

All my life her handwriting was the steadiest thing about her. It was the hand on the overdue slips, the hand in the margins of my homework, the hand that taught me cursive at the kitchen table with a pencil she'd sharpened with a knife. I'm not alarmed. It's still her. But I've started keeping things I used to throw away: the grocery lists, the notes on the fridge, a sticky note on my car that said "TIRES." I couldn't tell you what I'm keeping them for.

Whose handwriting would you know anywhere?

I'd forgotten that. I'd forgotten a lot of it. I'd remembered winter here as a story I told people in Seattle, and the story was true, but it was missing the part where the car makes a noise when you start it that sounds like an apology.

At the office, the frost grew on the inside of the windows. We have tall windows, which is half of why we took the room, and by Tuesday each pane had a forest of white ferns in its lower corners, thick enough to write in with a fingernail. Owen wrote the date in one. I wrote the temperature in another. The radiators knocked all day, at full stretch, doing their honest best, and we worked in our coats until about eleven.

At ten on Tuesday the man who owns the print shop downstairs came up the stairs, which he has never done, with a space heater under one arm. He has run that shop for thirty-one years and has opinions about paper weights that he'll share if you stand still. He set the heater down, told us to leave the kitchenette faucet dripping overnight or we'd be calling a plumber who wouldn't come, and said he keeps the shop warmer than he needs on mornings like this, because heat rises, and we're welcome to it. Then he went back down. The heater says "PROPERTY OF THE PRINT SHOP" on a label in his handwriting, in case we get ideas.

My mother is a few minutes away and perfectly capable, as she'll tell anyone, but on the worst days I had her groceries delivered so she wouldn't drive, the way I used to from Seattle. She called to say the oranges were very good and the delivery man was very young and she had given him cocoa.

It's supposed to get above freezing this week, and people at the grocery store are already talking about it like a holiday. Everything is relative.

What's the coldest you've ever been, and what got you warm again?

• The Underground Man, Ross Macdonald. On Jonah's word, from last New Year's Eve. A small boy goes missing while a wildfire comes down the hills, and Archer finds an old crime underneath, as he always does. Sadder than Chandler, and more patient. I've ordered three more.
• Iron Lake, William Kent Krueger. A murder in a small town in northern Minnesota in the dead of winter. My mother had it on her shelf for twenty-five years and handed it to me in March, saying "For your first winter back." It's set up the road from here, and it made me buy the boots.
• The Hunter, Tana French. Back to the village in the west of Ireland from The Searcher. Slow and deep and dreadful in the best way.
• James, Percival Everett. Huckleberry Finn, told by Jim. I read it in a day and then sat in the car outside the office for a while before I could go in.
• The Sentence, Louise Erdrich. A reread, now that Minneapolis is a drive away instead of a flight. A haunted bookstore in Minneapolis, in 2019 and 2020. I lived in that city for four years and knew every street.
• Farewell, My Lovely, Raymond Chandler. A reread, for reasons regular readers will understand.
• The Murder of Roger Ackroyd, Agatha Christie. A reread, my first since I was twelve. Knowing, I got to watch the trick being done, which is its own pleasure.
• Death at the Sign of the Rook, Kate Atkinson. Jackson Brodie, some stolen paintings and a country house. Funny, and kind about people, which is rarer than it should be.
• We Solve Murders, Richard Osman. A new set of people, and he's already made me fond of them.

What should I read in 2025?