The Sister Who Never Knocked

They always told me I was an only child.

The photos on the wall said the same—just me. Birthday cakes with my name. Solo portraits in the hallway. The silence of a house that echoed only one set of footsteps. I never thought to question it—not until the dreams began.

When I was little, I used to wake up in the middle of the night and sit at the end of my bed, convinced someone had just walked out of the room. Not a stranger. Not a monster. But someone familiar. Like the memory of a song you almost remember, but not quite. I’d feel the mattress shift. Hear the faint creak of the floorboards. A whisper, a giggle, a touch.

At first, my parents said it was just imagination.

“She has an imaginary friend,” my mom told guests with a smile.

“She talks to her in mirrors,” my dad added. “Calls her ‘the other me.’”

I believed them. For a while.

But then I started noticing things. A second toothbrush in the drawer, one I didn’t remember using. A crayon drawing I swear I never made—two girls holding hands in front of a house that looked like ours. One wore a blue dress, like mine. The other wore yellow.

By the time I was nine, I stopped asking about it. Adults tend to replace mystery with medication or ignore it entirely. And maybe I learned to do the same.

Years passed. I moved out, studied psychology, ironically. Tried to unpack my own mind through theories and textbooks. But nothing explained the grief I sometimes woke up with, like mourning a person I never met.

Then, last week, everything changed.

I went home to help my mom clean out the attic. My dad passed two years ago, and the house was quieter than ever. Dust clung to everything like memory. We spent hours boxing up old books, photo albums, school trophies. Then I found the shoebox.

It was tucked away behind a stack of Christmas decorations, wrapped in a faded scarf. My name was written on it in pen, along with another that had been smudged or rubbed out. Curiosity bloomed in my chest.

Inside were two pairs of baby shoes. One pink, one yellow. And a hospital bracelet with my name:

Baby A: Lillian

Then a second bracelet, barely legible:

Baby B: …

The name was torn off. The band discolored.

I stared at it, frozen. My mother saw it in my hands and her face collapsed. She didn’t try to take it away. She just sat down slowly on the dusty attic floor and said, “Her name was Eliza.”

She told me the truth: I was born a twin.

We came early. Complications.

Eliza lived for twelve hours.

I was stronger—just barely.

They hadn’t wanted to burden me with it. “Why plant sadness where it might never grow?” she said. “Why give you grief when you didn’t even know what you lost?”

But I did know. Somewhere deep, a piece of me had always known.

Suddenly, the dreams made sense. The second toothbrush. The mirror games. The constant pull toward something just out of sight.

I went home that night and sat with her shoes in my lap. I lit a candle and placed it by the window. Not because I thought she'd return, but because I wanted her to know I'd finally seen her.

I wrote a letter I’ll never send.

Dear Eliza,

I don’t know if spirits remember their lives.

I don’t know if you’ve watched me all this time, or if you simply became part of the sky.

But I know you were real.

I know now why I felt half-formed some days.

Why I’d cry for no reason on birthdays.

Why I always paused before calling myself “an only child.”

You were the silence I never understood.

The echo in every empty hallway.

The reason I sometimes turned around, expecting someone to be there.

I carry you now, with knowledge instead of mystery.

With love instead of loss.

Wherever you are, I hope it’s full of yellow dresses, soft stars, and lullabies we never got to share.

Love,

Lily

The next morning, I looked in the mirror.

This time, when I saw her standing behind me, I didn’t blink.

I smiled.

And for the first time in my life, she smiled back.