"I guess I know that too, girlie," he says. "But to talk about her, how I met her. Stuff like that helps. Besides, you don't know. She might be there. You never know about these things."

He gives her a photograph of his wife.

"What was your wife's name?" the girl detective says.

"I've been trying to remember that myself," he says.

Some things that have recently turned up in bank vaults.

Lost pets. The crew and passengers of the Mary Celeste. More socks. Several boxes of Christmas tree ornaments. A play by Shakespeare, about star-crossed lovers. It doesn't end well. Wedding rings. Some albino alligators. Several tons of seventh-grade homework. Ballistic missiles. A glass slipper. Some African explorers. A whole party of Himalayan mountain climbers. Children, whose faces I knew from milk cartons. The rest of that poem by Coleridge. Also fortune cookies.

Further secret origins of the girl detective.

Some people say that she was the child of missionaries, raised by wolves, that she is the Princess Anastasia, last of the Romanovs. Some people say that she is actually a man. Some people say that she came here from another planet and that some day, when she finds what she is looking for, she'll go home. Some people are hoping that she will take us with her.

If you ask them what she is looking for, they shrug and say, "Ask the girl detective."

Some people say that she is two thousand years old.

Some people say that she is not one girl but many – that is, she's actually a secret society of Girl Scouts. Or possibly a sub-branch of the FBI.

Whom does the girl detective love?

Remember that boy, Fred, or Nat? Something like that. He was in love with the girl detective, even though she was smarter than him, even though he never got to rescue her even once from the bad guys, or when he did, she was really just letting him, to be kind. He was a nice boy with a good sense of humor, but he used to have this recurring dream in which he was a golden retriever. The girl detective knew this, of course, the way she knows all our dreams. How could she settle down with a boy who dreamed that he was a retriever?

Everyone has seen the headlines. "Girl Detective Spurns Head of State." "I Caught My Husband in Bed with the Girl Detective." "Married Twenty Years, Husband and Father of Four, Revealed to Be the Girl Detective."

I myself was the girl detective's lover for three happy months. We met every Thursday night in a friend's summer cottage beside a small lake. She introduced herself as Pomegranate Buhm. I was besotted with her, her long legs so pale they looked like two slices of moonlight. I loved her size eleven feet, her black hair that always smelled like grapefruit. When we made love, she stuck her chewing gum on the headboard. Her underwear was embroidered with the days of the week.

We always met on Thursday, as I have said, but according to her underwear, we also met on Saturdays, on Wednesdays, on Mondays, Tuesdays, and once, memorably, on a Friday. That Friday, or rather that Thursday, she had a tattoo of a grandfather clock beneath her right breast. I licked it, surreptitiously, but it didn't come off. The previous Thursday (Monday according to the underwear) it had been under her left breast. I think I began to suspect then, although I said nothing and neither did she.

The next Thursday the tattoo was back, tucked discreetly under the left breast, but it was too late. It ended as I slept, dreaming about the waitress at Frank's Inland Seafood, the one with Monday nights off, with the gap between her teeth and the freckles on her ass. I was dreaming that she and I were in a boat on the middle of the lake. There was a hole in the bottom of the boat. I was putting something in it – to keep the water out – when I became aware that there was another woman watching us, an older woman, tall with a stern expression. She was standing on the water as if it were a dance floor. "Did you think she wouldn't find out?" she said. The waitress pushed me away, pulling her underwear back up. The boat wobbled. This waitress's underwear had a word embroidered on it:

Payday.

I woke up and the girl detective was sitting beside me on the bed, stark naked and dripping wet. The shower was still running. She had a strange expression on her face, as if she'd just eaten a large meal and it was disagreeing with her.

"I can explain everything," I said. She shrugged and stood up. She walked out of the room stark naked and the next time I saw her, it was two years later and she was disguised as an Office Lady in a law firm in downtown Tokyo, tapping out Morse code on the desk with one long petal-pink fingernail. It was something about expense accounts, or possibly a dirty limerick. She winked at me and I fell in love all over again.

But I never saw the waitress again.

What the girl detective eats for dinner.

The girl detective lies down on her bed and closes her eyes. Possibly the girl detective has taken the fat man's case. Possibly she is just tired. Or curious.

All over the city, all over the world, people are asleep. Sitting up in my tree, I am getting tired just thinking about them. They are dreaming about their children, they are dreaming about their mothers, they are dreaming about their lovers. They dream that they can fly. They dream that the world is round like a dinner plate. Some of them fall off the world in their dreams. Some of them dream about food. The girl detective walks through these dreams. She picks an apple off a tree in someone's dream. Someone else is dreaming about the house they lived in as a child. The girl detective breaks off a bit of their house. It pools in her mouth like honey.

The woman down the street is dreaming about her third husband, the one who ran off with his secretary. That's what she thinks. He went for takeout one night five years ago and never came back. It was a long time ago. His secretary said she didn't know a thing about it, but the woman could tell the other woman was lying. Or maybe he ran away and joined the circus.

There is a man who lives in her basement, although the woman doesn't know it. He's got a television down there, and a small refrigerator, and a couch that he sleeps on. He's been living there for the past two years, very quietly. He comes up for air at night. The woman wouldn't recognize this man if she bumped into him on the street. They were married about twenty years and then he went to pick up the lo mein and the wontons and the shrimp fried rice, and it's taken him a while to get back home. He still had his set of keys. She hasn't been down in the basement in years. It's hard for her to get down the stairs.

The man is dreaming too. He's working up his courage to go upstairs and walk out the front door. In his dream he walks out to the street and then turns around. He'll walk right back up to the front door, ring the bell. Maybe they'll get married again someday. Maybe she never divorced him. He's dreaming about their honeymoon. They'll go out for dinner. Or they'll go down in the basement, down through the trapdoor into the underworld. He'll show her the sights. He'll take her dancing.

The girl detective takes a bite of the underworld.

Chinese restaurants.

I used to eat out a lot. I had a favorite restaurant, which had really good garlic shrimp, and I liked the pancakes, too, the scallion pancakes. But you have to be careful. I knew someone, their fortune said, "Your life right now is like a rollercoaster. But don't worry, it will soon be over." Now what is that supposed to mean?

Then it happened to me. The first fortune was ominous. "No one will ever love you the way that you love them." I thought about it. Maybe it was true. I came back to the restaurant a week later and I ordered the shrimp and I ate it and when I opened the fortune cookie I read, "Your friends are not who you think they are."