I OPENED THE WALL BEHIND MY LIBRARY—AND DISCOVERED WHY MY HOUSEKEEPER HAD BEEN TERRIFIED FOR YEARS.

For several seconds, neither Mia nor I moved.

The voice had been so faint that I almost convinced myself I had imagined it.

Then it came again.

“Help…”

Mia’s face went white.

“Mr. Duca…”

I held up my hand.

“Stay behind me.”

I stepped toward the bookcase.

My fingers found the narrow gap beneath the bottom trim again.

This time, I pulled.

Nothing.

I pulled harder.

The wood groaned.

Dust fell from somewhere above us.

Mia coughed.

“Go downstairs.”

“But—”

“Now.”

She nodded.

I watched her hurry toward the door, one hand supporting the sleeping baby against her back.

Then I heard it.

Three knocks.

Closer than before.

Knock.

Knock.

Knock.

I grabbed the edge of the bookcase with both hands.

The first panel shifted.

Barely an inch.

Cold air rushed through the opening.

The smell reached me next.

Damp stone.

Mold.

Something metallic.

I pulled again.

The entire bookcase moved.

Not a bookcase.

A door.

A hidden door.

Behind it was a narrow pᴀssage descending into darkness.

I stared into it.

Eleven years.

I’d lived in this house for eleven years.

I had never known this existed.

Then something scraped against the stone below.

I reached for the flashlight on my phone.

“Hello?”

No answer.

I stepped through.

The pᴀssage was barely wide enough for my shoulders.

Old brick walls pressed in on both sides.

Water dripped somewhere ahead.

Then I saw the marks.

On the wall.

Small scratches.

Hundreds of them.

Some were deep enough to expose the brick.

I moved closer.

Names had been carved into the mortar.

Dates.

Initials.

Some were decades old.

Others were recent.

One name stopped me.

GRACE HARPER.

I stared at it.

My housekeeper.

Beneath her name was a date.

Three months earlier.

My pulse jumped.

Then I heard footsteps.

Not behind me.

Ahead.

I raised the flashlight.

“Who’s there?”

Silence.

I continued forward.

The pᴀssage opened into a small room.

A chair stood in the center.

A metal table.

Old blankets.

Water bottles.

And on the wall—

pH๏τographs.

Dozens of them.

My house.

My study.

My front gate.

Grace entering through the servants’ entrance.

Mia walking home from school.

Lily being carried upstairs.

My blood ran cold.

Someone had been watching my family.

For how long?

I stepped toward the table.

A stack of folders lay beneath the pH๏τographs.

The first contained my name.

The second contained Grace’s.

The third contained Mia’s.

I opened Grace’s.

Medical records.

Employment history.

Addresses.

PH๏τographs.

Then one page made my hands shake.

It was a letter.

Written in Grace’s handwriting.

If anything happens to me, do not let Mia enter the library.

I read it again.

Below it was another sentence.

She must never know what is behind the wall.

A sound came from the far end of the room.

I turned.

There was a second door.

Locked.

From behind it came a soft scratching.

Then three knocks.

I stepped closer.

“Who’s there?”

A voice answered.

Weak.

Terrified.

“Please…”

I grabbed the handle.

It wouldn’t move.

I looked around.

Then I saw a key on the table.

Beside it was a pH๏τograph.

A younger Grace stood beside a man I had never seen before.

On the back of the pH๏τograph were four words:

He knows about Mia.

My phone suddenly vibrated.

I looked at the screen.

Grace was calling.

I answered.

“Grace?”

For several seconds, there was only breathing.

Then her trembling voice came through.

“Mr. Duca…”

“Where are you?”

A pause.

Then:

“Please get Mia out of that house.”

My blood went cold.

“Why?”

Her voice broke.

“Because the person behind the wall isn’t the person you should be afraid of.”

I stared at the locked door.

“Then who?”

Grace whispered four words.

“The person who built it.”

The call went ᴅᴇᴀᴅ.

Behind the door, something moved.

And then, for the first time, I heard the lock turning from the inside.