She looked pale.
She was still wearing her coat.
The moment she saw Mia, she rushed forward.
“Mia!”
Her daughter ran into her arms.
“I’m sorry, Mama.”
Grace pulled back.
“What happened?”
Mia pointed toward me.
“Mr. Duca knows.”
Grace’s face drained of color.
She looked at me.
I expected fear.
Instead, I saw exhaustion.
“I didn’t steal anything.”
“I know.”
“I wasn’t trying to cause trouble.”
“I know.”
She looked toward the library.
Then she closed her eyes.
“You heard it.”
I nodded.
Grace sat down.
For the first time in eight years, she told me everything.
She had heard the knocking months earlier.
At first, she thought it was plumbing.
Then she noticed the sounds came at nearly the same time each night.
She had told her supervisor.
She had been dismissed.
She had mentioned it to another employee.
Nothing happened.
Then she stopped talking about it.
Not because she didn’t believe the sound.
Because she couldn’t afford to become the woman who caused problems.
And that was when I understood the real tragedy.
Grace had been protecting her job.
Mia had been protecting Grace.
And I had been walking through the middle of all of it without seeing anything.
I turned toward Grace.
“You’re not losing your job.”
She stared at me.
“Sir?”
“You heard something strange in my house and were afraid to tell me.”
She lowered her eyes.
“I thought you’d blame me.”
“I should have asked.”
Her eyes filled with tears.
I looked away for a moment.
Then I said, “You should never have had to send your six-year-old daughter to clean my study at two in the morning.”
Grace covered her face.
“I’m sorry.”
“Don’t apologize.”
I paused.
“Just don’t do it again.”
She nodded.
I arranged for a doctor to see her that morning.
I also made sure she had paid leave until she recovered.
But there was something else I needed to do.
I returned to the library.
The detectives had left the hidden passage open.
Sunlight was beginning to enter through the tall windows.
The same wall that had looked solid for years now stood open.
Mia appeared behind me.
She had Lily in her arms.
“Mr. Duca?”
I turned.
“Yes?”
“Did you find who was knocking?”
“Not yet.”
She frowned.
“Then who’s going to knock tonight?”
I looked at the passage.
“I don’t know.”
She thought for a moment.
Then she said, “Maybe you should listen.”
I smiled despite myself.
“Maybe I should.”
She walked closer.
