David and Petra arrived at the end of the dripping stone passage.

“Ah, here is the way in.”

They stopped beside a small metal door that looked as though it was rarely used. There was a vertical bar up one side with a padlock through it. Petra gave David a crafty look, then kicked the bottom of the bar with her foot. The padlock dropped off, and David saw that it had been broken at some point in the past.

“Did you do that?” he asked.

“I don’t like locks,” said Petra. “Unless I’ve locked them myself. Come.”

The door led into a larger passage, still cut roughly from the rock, but in better condition. The light was more stable here. Soon David noticed that the ceiling had become vaulted and was made of white stone, greenish-gray with age and damp, and hung with cobwebs. They had reached the cellar. It was pitch-black from there on and David cursed himself for not thinking to bring a flashlight.

“This way,” said Petra, walking out into the shadows. She moved her arm, and a shaft of light sprung from a flashlight in her hand.

The cellar was enormous, with arched side bays full of boxes and crates, and high, cobwebbed racks, the odd wine bottle still resting there. Petra clearly knew where to go, and soon they were walking up stone steps, picking their way carefully in the little patch of light pointed at the girl’s feet. At the top was a large wooden door. Petra turned the handle and pushed it open.

“Wait a moment,” said David. “Aren’t there security cameras or anything?”

Petra shrugged. “I have never seen such a thing here.”

They stepped through the door and walked out from under an enormous carved staircase that dominated a paneled hallway. In front of them was a broad, glass-paned double front door, and on each side of the hall there were further doorways. Through one of these, David caught a brief glimpse of furniture draped in dust-sheets, stacked files, and an overhead projector, and he remembered that the Project had actually used this building until quite recently. Now, though, it felt abandoned.

Petra handed him the flashlight.

“The study is on the top floor,” she said. “This was your idea. You lead the way.”

They began to climb.

When they reached the first floor, David glanced uneasily down the long corridors. The ground floor had appeared well kept, but up here the building seemed in poor condition. The shards of light that entered between the wooden slats left crooked bars of shadow on the wall. David felt cold as they continued up the stairs, the wooden steps creaking beneath their feet.

On the next floor the shutters were also closed, and the flashlight illuminated great looping cobwebs and lost its brightness in the dust. Petra, who had kept behind David as they climbed, suddenly walked straight to a window in the middle of the landing. She climbed up onto the wide sill and undid the catch.

“What are you doing?” whispered David.

“I want to see the view,” said Petra, not whispering at all.

She gave the tall shutters a determined shove. They fell wide open, and David welcomed the freshness of the cool mountain air after the air-conditioned base. Beyond was a far-reaching view along a valley, ringed with the snow-capped peaks of the Alps. The late afternoon sun spilled on to the landing, and Petra stood in its light, breathing deeply. David saw that there were some things on the windowsill — magazines and books, a cushion, and an empty teacup.

“I haven’t been here for a while,” said Petra, jumping back down. “But now you know all my secrets. The study is along there on the left.”

Leaving the window open, they continued down the corridor until they arrived at a closed door. It was locked.

“I don’t suppose you know where the key is,” said David, without much hope.

“Why bother with a key?” Petra said. “I didn’t have a key when I first came to the château. And you’re stronger than I am.”

“Break in, you mean?” David was surprised. “But what about alarms? And won’t Misty notice? I thought she was everywhere in Unsleep House.”

“Only in the new bits. There’s no Misty up here.”

David looked at Petra and remembered that he still had a lot to prove to her. He turned back toward the door. It was old, and the wood was dry. He could feel Petra watching him, but even if she hadn’t been, there was too much at stake to let a few boards of decaying oak stop him now. He stepped back and hurled himself at the door.

He’d expected to be flung back with a bruised shoulder, but instead the brittle wood just split right down the middle, disintegrating into splinters and dust. He shone the flashlight inside.

Everything in the room was covered in white sheets, but there was one large rectangular object in the middle of the room that was obviously a desk, and several others that could have been armchairs. The bookcases were also covered.

David smiled. He was standing in his grandfather’s own room, and really standing there, not dreamwalking. This was the strongest physical connection he’d yet had with the boy from his dream, though it was also the closest he could ever get to him in the present. Sir Edmund Utherwise had lived out his natural span — dreamwalking was now their only means of contact. David found himself fingering the notebook still in his pocket.

“Are we looking for something specific?” said Petra, breaking his thoughts.

David walked over to the nearest bookcase, pulled the dust-sheet down, and swung the flashlight across the shelves. Books, nothing more. He walked to the next case and did the same.

This time his flashlight revealed the wall of photographs he’d seen behind Sir Edmund in the photo. He quickly scanned the frames until he found the one he was looking for. It was exactly where it should have been. He took it down and shone the flashlight at it.

“Here, look,” he said. “You see this group of people? I think that must be Eddie and his mother saying good-bye to his father. It dates from around the time I first started visiting him. The end of 1939, I think, when the war started. Anyway, you see that girl there? I’ve seen her before. She was a maid or something at Eddie’s house.”

“You come from a rich family,” said Petra.

“Me? No! Well, in Eddie’s time maybe — I don’t live like this. But listen, this girl’s name was Kitty or Kat or something. I saw her come to Eddie’s door a few times. He never let her in when I was there, but I think she saw me at least once. The thing is, they didn’t behave like she was just his servant. It was more like they were friends.”

“I see,” said Petra, taking the photo. “I do remember her from my time watching you and Eddie, but she was just listed in the Archive as a resident in the building and was not part of my briefing. I was only there to watch you, David, and I was very careful. Eddie already had one ghost; he didn’t need another. You think she might be a clue to finding Eddie?”

“Well, yeah. Everyone assumes that because Eddie was such a loner, I must be his best friend or something, but why shouldn’t he have had someone else? I mean, how much does anyone here really know about Eddie when he was my age? And if you kept seeing a ghost, wouldn’t you want to tell someone? Ever since the professor first told me Eddie had gone missing, I’ve been trying to remember something Eddie said when I last saw him. It came back to me when I saw this picture. Eddie said he shouldn’t have trusted me and that someone named Kat had told him so.”

“Meaning this girl?” said Petra.

“I think so. The point is, I don’t know where Eddie’s run off to, but maybe she does. I want to go back in time and talk to her.”

“The professor needs to know about this,” said Petra. “We should get back.”

David followed her to the door, shining the flashlight once more around room as he went. He stopped.

“Wait.”

He walked back to the wall of photos and picked up another. It showed a man and a boy shaking hands in the Map Room of Unsleep House, and behind them, looking on and smiling, was the elderly Sir Edmund Utherwise. The boy was Adam Lang, and the person he was shaking hands with was someone David knew instantly. It was his own father.

He held the picture up to Petra.

“If Misty isn’t here, perhaps you can give me a straight answer now,” he said, unable to keep the anger from his voice. “What has my dad got to do with this place?”

Petra came back over. She looked awkward and embarrassed.

“I never wanted to lie to you. They told me that you shouldn’t know, not until the crisis with Adam was over.”

“Know what?”

Petra bit her lip.

“Tell me!”

“David, you grew up thinking that your father was a soldier, but that is not true. He was part of the Dreamwalker Project.”

David said nothing. He’d kind of worked that out for himself. But seeing his dad with Adam was horrible.

“He was a trainer,” Petra continued. “He taught us dreamwalking technique. He was a dreamwalker himself as a boy, and like many he stayed on to work here as an adult. They had to think of something to tell your family, so the soldier thing became his cover story. Sometimes the only way to keep a secret is to tell a lie.”

“But why keep it from me now?” David said. “He was my dad. Why shouldn’t I know?”

“Richard Utherwise, your father, was Adam’s mentor. He was personally responsible for training and guiding the Project’s best dreamwalker, and he spent a lot of time working closely with Adam. Security thought this would upset you and cloud your judgment. The professor agreed. I’m sorry.”

David looked at the photo again and felt sick.

“If my father wasn’t a soldier,” he said after a long silence, “how did he die?”

Petra stared at her feet.

“An accident. He fell down some stairs in the base. Just a stupid accident.”

David looked at the picture again, then threw it across the room. It shattered against the wall.

“I want to get out of here.”

Petra said nothing as she took the flashlight and led the way back down the corridor. David followed her in silence. All he could think of was the fact that his father had spent far more time with Adam than he had with his own son. And no hero ever dies just falling down the stairs.

No hero at all.

They reached the top of the steps but David was too lost in his own thoughts to notice what was happening. Then, as he took the first step, he saw that Petra had gone, and the flashlight beam was nowhere to be seen. He froze.

“Petra?”

Nothing.

He looked back down the corridor to where they had been. It was dark, easily dark enough to hide someone. And David thought he could see a shape in the gloom, but there was no way it could be Petra. A sudden wave of panic chased away the misery over his father’s betrayal, and he ran down the stairs to the hall.

“Petra! Where are you?”

Without the flashlight, the dark closed around him. Desperate to get out, he made straight for the front door where the last of the evening light was still coming through the glass. He grabbed the door handle.

Something dark and man-shaped stepped across the outside of the door. David staggered back and turned.

A head suddenly appeared in a blaze of light right in front of him. David let out a whimper.

“Boo,” said the unsmiling, flashlight-shadowed face of Roman.

Lights came on and David saw that he was surrounded by armed security men.

He was actually relieved.