I walked to the door and stood in front of it, staring at the locks my mother had installed years ago. Two deadbolts and a chain. She always said you could never be too careful.

I wondered what she would think if she could see me now, standing here in the middle of the night, about to open the door for someone who might be her ghost. My hands moved before my brain could talk me out of it. I turned the first deadbolt, then the second.

I slid the chain out of its track and let it hang loose against the frame, and then I turned the handle and pulled the door open. She was standing right there, just a few feet away from me. The porch light from the neighbor’s house cast a soft glow across her face, and I could see every detail.

The fine lines around her eyes. The small scar on her chin from a cooking accident when I was ten. The way her gray hair curled slightly at the ends, because she never could get it to lie flat.

She looked exactly like my mother. Exactly.

“Hi, sweetheart,” she said softly.

I couldn’t move. I couldn’t speak. I just stood there in the doorway, staring at this impossible woman who wore my mother’s face like it belonged to her.

The cold February air rushed past her and into the house, but I barely felt it.

“You’re not real,” I finally managed to whisper. “You can’t be real. I watched her die.”

“I held her hand while she took her last breath. I picked out the dress she was buried in.”

The woman’s eyes filled with tears, and something about that broke me even more. Ghosts weren’t supposed to cry. Hallucinations weren’t supposed to look so heartbroken.

“I’m real,” she said. “I’m just not who you think I am. Can I come inside? Please. I’ll explain everything.”

I stepped back without saying anything, and she walked past me into the house. She moved carefully, looking around at the walls and the furniture like she was seeing it all for the first time. Her fingers brushed against the back of the couch, and she paused in front of the mantle where I kept my mother’s photograph.

“She was beautiful,” she said quietly. “I always wondered what she looked like.”

I closed the door behind her and leaned against it. “Who are you?”

She turned to face me, and I could see the resemblance even more clearly now. Same height, same build, same way of holding her hands clasped in front of her body. But there were differences too.

Tiny things I hadn’t noticed through the peephole. Her eyebrows were slightly thinner. Her posture was a little straighter.

She carried herself like someone who had lived a different life.

“My name is Marlena,” she said. “Marlena Davis. And I’m your mother’s twin sister.”

The words hit me like a punch to the chest. I shook my head, refusing to accept what she was saying.

“That’s impossible. My mother didn’t have a twin. She didn’t have any siblings except Aunt Delia.”

“She didn’t know about me,” Marlena said. “Neither of us knew. We were separated at birth.”

“Different adoptions. Different families. Different states. I grew up in Vermont with parents who loved me.”

“And I never knew I had a sister until six months ago.”

She reached into her cardigan pocket and pulled out a folded piece of paper. She unfolded it slowly and held it out to me. It was a DNA test result from one of those ancestry websites.

I’d seen commercials for them a hundred times. The paper showed a match. A 99.98% probability of a full sibling relationship with someone named Renata Monroe.

“I found her too late,” Marlena continued, her voice breaking. “By the time I tracked her down, she was already gone. I missed her by three years.”

“Three years, Sadie. I had a sister my whole life and I never got to meet her.”

I took the paper from her hands and stared at it. The numbers blurred as tears filled my eyes. This woman wasn’t a ghost.

She wasn’t a hallucination or a scam artist or some cruel trick. She was my mother’s other half. The piece of her that had been missing all along.

“The phone number,” I said. “How did you get her phone number?”

Marlena wiped her eyes with the back of her hand. “I contacted the phone company. I told them I was settling her estate and needed the number reactivated for records purposes.”

“They believed me. I just wanted something that connected me to her. I never meant to scare you.”

“I’ve been watching you for weeks, trying to find the courage to introduce myself. Tonight I saw your lights go off and I panicked. I called before I could stop myself. I’m so sorry.”

I looked at her face again, searching for my mother in her features. She was there. She was everywhere.

The sound of sirens broke the silence between us. Red and blue lights flashed through the front window, painting the walls in alternating colors. A few seconds later, there was a loud knock at the door, and I heard Aunt Delia’s voice calling my name.

I opened the door to find her standing there with two police officers behind her, her face pale and terrified.

“Sadie, are you okay? What’s going on? Who’s in there with you?”

I stepped aside so she could see Marlena standing in the living room. Delia froze in the doorway, her mouth falling open. She grabbed the doorframe to steady herself, and I watched the color drain from her face completely.

She looked like she had just seen a ghost, which I suppose she thought she had.

“Oh my God,” she whispered. “Renata?”

“No,” I said quietly. “Her name is Marlena. She’s Mom’s twin sister.”