THE HOUSEMAID’S MOTHER HAD BEEN MISSING FOR SIX MONTHS—THEN A PHOTOGRAPH AT A BIRTHDAY DINNER PROVED SHE HAD BEEN INSIDE THE MANSION YESTERDAY.

My mother's apartment looked smaller than I remembered.

Maybe fear did that to rooms.

Maybe six months of absence had drained the life from the place until all that remained were square walls and objects waiting for someone who had not come home.

Gareth stood just inside the door while Rowan's men swept the rooms.

Nothing had been disturbed since the police had searched after my mother disappeared. Her shoes were still lined beneath the coat rack. A grocery list was held to the refrigerator by a tomato-shaped magnet. Two mugs sat upside down beside the sink.

I had been here dozens of times since April.

I had never found the blue tin.

"Under the bed?" Gareth asked.

"When I was nine."

We went to the bedroom.

The bed frame was iron, painted cream. I dropped to my knees and looked underneath.

Dust.

A shoe box.

One lost slipper.

No blue tin.

I pulled open the closet, then the old cedar chest, then the narrow drawers of her dresser.

Nothing.

"She moved it," I said.

Gareth leaned against the doorframe, watching the room rather than me.

"Would she throw it away?"

"No."

"Then she hid it better."

I wanted to tell him I knew my mother better than anyone alive.

But that had stopped feeling true.

She had worked for his family and never told me.

She had known Thomas Vale.

She had hidden evidence from men dangerous enough to move her through a mansion behind walls.

What else had she decided I was safer not knowing?

I sat on the edge of the bed.

"When I found it, she didn't just take it away. She made me promise not to touch her private things again."

"Did you?"

"Of course not. I was nine. I opened everything after that."

A small smile touched his mouth despite the night.

"Good."

"Good?"

"Curiosity is useful."

"It got me grounded for two weeks."

"Still useful."

I looked around the room again.

My mother's idea of hiding something from a curious child would not have been complicated. She knew I climbed chairs, opened boxes, crawled under furniture.

She also knew what I refused to touch.

"The sewing machine."

Gareth followed my gaze.

An old black sewing machine sat beneath the window beneath a fitted vinyl cover.

I crossed the room and pulled off the cover.

The machine had belonged to my grandmother. Heavy metal. Gold lettering. The wooden base was scratched from decades of use.

I lifted it.

Nothing.

Then I remembered my mother changing the bobbin when I was little. A shallow drawer beneath the machine slid sideways.

I opened it.

Thread.

Needles.

A thimble.

And a brass key.

Not a house key.

Too small.

Tied to it was a blue string.

Gareth crouched beside me.

"No tin."

"But maybe a way to find it."

On the bottom of the drawer, written in pencil so faintly I nearly missed it, was a line of numbers.

17-3-9-12-5.

Gareth photographed it.

"Code?"

"Maybe letters. Q-C-I-L-E if one is A. That means nothing."

I stared.

Then the numbers clicked into place.

"Not letters. Bus stops."

"Your mother used bus numbers with you."

"Not exactly. She used routes. But she loved doing crossword puzzles and writing grocery lists in ridiculous little codes."

I took out my phone and opened a map.

17th Street.

Third Avenue did not fit Chicago.

Nine, twelve, five.

Then I saw it.

"Locker numbers."

"Where?"

"Union Station has old baggage lockers?"

Gareth shook his head. "Not public ones anymore."

"What about the church basement?"

He looked at me.

I explained.

St. Casimir's, the school Thomas had named for midnight, belonged to the parish my mother attended when I was a child. The church basement once had rows of metal pantry lockers for volunteers. Each section was numbered.

Rowan entered the bedroom.

"Boss. We found something in the hallway wall."

A rectangular patch of paint behind a framed landscape looked newer than the rest.

One of Rowan's men used a thin tool to pry loose the baseboard.

Behind it was a cavity.

Empty.

Except for a strip of blue paint on the wood.

Someone had removed the tin.

Recently.

My stomach dropped.

"Thomas already came here."

Rowan shook his head.

"Maybe. But the building camera shows no one matching him."

"Then who?"

He held up a printout.

"Althea."

The hallway security camera had captured her entering my mother's building five months earlier.

She wore sunglasses and carried a large handbag.

She stayed sixteen minutes.

I stared at the image.

"She was here one month after my mother disappeared."

Gareth's face became unreadable.

"Take her to the study when we get back."

"What if she took the tin?"

"Then we ask until she tells us where it is."

Before we could leave, someone knocked on the apartment door.

Three short taps.

A pause.

Two taps.

My mother's knock.

I ran.

Rowan caught my shoulder just before I reached the door.

"Wait."

Gareth drew back from the entry, nodding to one of the guards.

The guard opened the door from the side.

The hallway was empty.

On the floor sat a white bakery box.

My heart began pounding.

The same kind of box Althea had used for the little birthday cake beside my mother's photograph.

Rowan brought it inside and opened it.

No cake.

Only a cassette tape.

And a handwritten note.

SABELLA - PLAY THIS BEFORE MIDNIGHT.

The handwriting was my mother's.

I knew every curve.

I had seen it on birthday cards, grocery lists and notes taped to my lunch bag when I was a child.

My hands shook as I picked up the cassette.

"How are we supposed to play this?"

Gareth looked around the apartment.

"Your mother kept a sewing machine older than both of us. I doubt she threw away every cassette player."

He was right.

There was one in the kitchen cabinet above the refrigerator.

I had forgotten it existed.

I put in the tape.

For three seconds there was only static.

Then my mother's voice filled the kitchen.

"Sabella, if you are hearing this, somebody has finally made you look where I should have let you look years ago."

My knees weakened.

I sat down.

"I am sorry. I wanted your life to begin after mine, not inside it."

I covered my mouth.

Gareth stood perfectly still.

The tape continued.

"Thomas Vale is alive. Julian Mercer helped him disappear. But Thomas is not the person I fear most."

Gareth's eyes lifted.

"The person I fear is inside the Vale house."

Static crackled.

"Celeste kept proof in a place Thomas never understood because he thought women hid important things in safes. She did not. She hid them in memories."

A pause.

"The blue tin does not contain the proof. It contains the map."

I looked at Gareth.

The recording went on.

"If Thomas asks for the tin, give him nothing. If Julian says he can protect you, believe nothing. And if a Marlowe offers you kindness, ask what they already know."

Althea.

Her father.

My pulse hammered.

"The key in my sewing drawer opens locker seventeen, third row, cabinet nine, shelf twelve, compartment five."

I stared at the penciled numbers.

My mother had given me the sequence after all.

Then her voice changed.

It became softer.

"Sabella, I was not taken in April."

I stopped breathing.

"I left."

The kitchen disappeared around me.

"I left because I saw Thomas outside your building. I knew if I stayed, he would use you to reach me. I went to someone I thought I could trust. For five months, I moved between safe places. Then I made one mistake."

Static.

"I trusted Althea."

Gareth closed his eyes once.

"She told me she wanted to help you. She said Gareth could not be told until she knew who inside his organization still served Thomas. I believed her."

My throat tightened.

"Three weeks ago, she delivered me to Julian."

The tape clicked softly.

Then my mother's voice returned, weaker.

"If Althea says she did it to protect Gareth, ask her why she was paid."

The recording ended.

No one moved.

Then Gareth's phone buzzed.

Rowan checked the screen.

A message had arrived from the estate.

ALTHEA IS GONE.

Gareth looked at the kitchen clock.

10:37 p.m.

Midnight was less than ninety minutes away.

I picked up the brass key.

"We're going to St. Casimir's."

Gareth reached for his coat.

"Yes."

"And if Althea took the blue tin?"

His expression went cold.

"Then tonight she is going to learn the difference between being afraid of Thomas Vale and being caught lying to me."

As we left, I stopped in the doorway and looked back at the apartment.

For six months, I had imagined my mother dragged from this place against her will. The truth was somehow worse and better. She had walked out on purpose. She had been brave enough to disappear in order to keep me safe.

And I had spent every night believing she might have chosen not to come back.

Gareth seemed to understand why I couldn't move.

"She left for you," he said.

I nodded.

"I know."

"Then find her for the same reason."

I closed the apartment door.

This time, when I walked away, I did not feel abandoned.