"Because he believed you would be safer without him."

I laughed bitterly.

"Everyone keeps saying that."

My mother reached for my hand.

"Please. Give me the key."

I stepped back.

"No."

"Listen to me."

"Not this time."

She looked toward the glass roof.

Then she whispered:

"Martin knows about the winter garden."

A sharp crack sounded outside.

The glass door shattered.

My mother screamed.

I dropped to the floor as a bullet struck the wooden table.

Someone was standing beyond the broken glass.

A tall man in a dark coat.

He raised his weapon again.

My mother pulled me behind the stone planter.

"Run!" she shouted.

We scrambled through the side door and into the garden.

Another shot shattered the glass above us.

I reached the gate and looked back.

The man had entered the winter garden.

He was searching the floor.

Searching for the key.

Then he turned toward us.

Even at a distance, I recognized the notch in his left ear.

Adrian Cross.

The man who had worn my father's face.

He smiled.

And called out:

"Tell Robert I'm tired of waiting."

We reached the road before the first police vehicle arrived.

Bennett pulled up beside us, his lights flashing.

He jumped out.

"What happened?"

"Adrian Cross," I said. "He's inside."

Bennett drew his weapon and ran toward the garden with two officers.

My mother collapsed against the side of the car.

I knelt beside her.

"Are you hurt?"

She shook her head.

Then she looked at my hand.

The key was still there.

"Don't let him take it," she whispered.

"I won't."

She gripped my wrist.

"There's something else you need to know."

"What?"

"Robert didn't go beneath the river to rescue Daniel."

I frowned.

"Then why did he go?"

My mother looked toward the winter garden.

"Because Daniel wasn't the only person being held there."

I stared at her.

"Who else?"

She swallowed.

"Adrian's daughter."

PART THIRTEEN — THE CHILD IN THE HOLDING CHAMBER

My mother refused to say another word until we were inside the police station.

Bennett returned from the winter garden with an empty hand and a furious expression.

Adrian Cross had escaped.

He had left through a narrow service gate behind the property, crossed a field, and disappeared into the trees before the officers reached the road.

But he had not found the key.

That was the only good news.

The second was that he had left something behind.

A photograph.

It was wedged beneath the loose floorboard where my mother had hidden the leather pouch.

The picture showed a little girl sitting on a concrete floor. She was perhaps six years old, with dark hair and a pale dress. Behind her stood a metal door marked with the same symbol as the key.

On the back was a date.

MARCH 12, 1997.

And a name.

LILY CROSS.

I placed the photograph on the table.

"Who is she?"

My mother stared at it.

"Adrian's daughter."

"Why was she beneath the river?"

"Because Adrian believed she had seen something she shouldn't have."

"What?"

"I don't know."

"You said my father went looking for Daniel. Now you're telling me he went looking for Adrian's daughter."

"Both are true."

"How?"

My mother rubbed her forehead.

"After Robert escaped Northfield, he discovered that Adrian had a family. He also discovered that the company had been using children as messengers in the underground system. They were small enough to pass through the maintenance corridors without attracting attention."

I felt sick.

"They used children?"

"Only when they needed to move things through the narrow sections. They told the children they were helping repair water pipes."

"How many?"

"I don't know."

"Was Elena one of them?"

My mother nodded.

"She was the first."

I looked down at the photograph.

The girl in the yellow raincoat.

The rabbit.

The fake key.

Everything began to take on a darker meaning.

"Was Elena forced to carry the key?"

"Yes. She didn't understand what it opened. She only knew that her father had told her to keep it safe."

"And Lily?"

"She was born later. Adrian brought her into the system when she was four."

"Why?"

"Because he wanted to keep her close. He believed someone was trying to take her away."

"Who?"

"Robert."

I stared at my mother.

"My father was trying to rescue her?"

"Yes."

"Then why did Adrian pretend to be him?"

"Because Adrian needed access to the family. He wanted to know where Robert had hidden the real records."