When a fireball suddenly appears (and there’s never any warning) it is such an astonishing moment that most people are spellbound.

—O. Richard Norton, Rocks from Space

BIRDIE COMES INTO my room and wakes me up, pulling her red sled behind her. In her other hand she holds her yellow stuffed duck, Lilygirl. At night Birdie sleeps with Lilygirl on her crib mattress in Mom and Dad’s room down the hall.

“Mama sleep,” Birdie tells me. “Dad sleep.”

Maybe what fell from the sky came to Birdie, who cares more than the rest of us what’s up there past the weather vane spinning in the wind. Birdie gets her name from the first words she spoke. “Me Birdie,” she said, pointing at a flock of geese flying south before winter. Their honking was loud and sad at the same time.

I’ve been alive for one hundred percent of Birdie’s life, and she’s only been alive for twenty percent of mine, but I feel like there was never a time I didn’t know her.

I’m always doing the math in my head. When I’m twenty, Birdie will be twelve. When I’m fifty, Birdie will be forty-two. The longer we both live, the greater the percent of my life I’ll have known her. When I’m ninety-nine and Birdie is ninety-one, I’ll have known her ninety-one-point-nine-one percent of my life.

Sometimes I think Birdie is lucky because she has eight more years where she doesn’t have to worry about being a dowser or not. She can just play with Lilygirl and sled and watch for birds and swing on Nana’s swing.

“Mom and Dad will be awake soon. Want to go see something in the field?” I ask her.

“Slide down,” Birdie says.

“Sure. But I want to show you something first.”

Birdie puts Lilygirl in her high chair.

“Be good,” she tells her.

I get dressed and help Birdie into her coat and boots. Her winter coat is as red as a cardinal’s and she rides on my back, my arms circling her skinny legs as I tromp toward the place where the dark shape came to rest during the night.

We walk past the garden covered in snow and ice, past the empty clothesline, past the blackberry patch into the wide, sloping field that goes from the old stone wall bordering it at the top down sharply to the road. The same field where James found the antler and Birdie sledded.

Something in the top corner of the field, below the hedgerow between our land and Braggy’s, looks like a giant boulder. It’s twice as tall as I am and wider on the bottom than on its flat top. It’s black and in the sun its surface shines like colored glass.