The gate swung open stiffly, as if it did not open often. Beyond was a garden with trees weighed down by their late-May green burdens, and crazy paving that stretched on until it was lost from view.

They went slowly down the garden path, Nick’s awareness of what was going on ebbing and fading with every step. The garden was a wild tangle that had clearly been left to decay for years; briars formed nightmare patterns against Nick’s eyelids as his eyes closed. Alan’s voice cut across his consciousness, saying his name, and Nick opened his eyes again with an effort.

In front of them now was a large white house, rising above them like a sheer white cliff. It was so large that it seemed to demand decoration, the decency of pillars and balconies, but here behind the gates there was no such pretense. There was only the severe white building, stretching up five floors. Above the large door were letters raised in gold.

The words swam before Nick’s eyes, gleaming fish that wanted to escape and would not form a coherent pattern, and then they stilled. Nick could feel his body now and it felt heavy, so heavy that he could not hold himself up.

The gold letters stayed for a moment, pinned up against the blackness, when his eyelids dropped and he fell forward.

THE HOUSE OF MEZENTIUS, the shining words read, and below that: THEIR NAME IS LEGION.

Nick woke in darkness to the sound of screams.

The darkness he solved by reaching out and turning on the lamp on the table beside his bed, but the screams were different. He sat up, noting with relief that his muscles and sinews now remembered they were his and obeyed him. He slipped out of the tangled embrace of sheets to have a look around. The room had a high ceiling, and little scalloped bits at the corners of said ceiling. His bed was big, with a carved oak headboard.

The screams were faint. Nick judged that they were muffled by thick walls, rather than all that far away.

The heavy door, also polished oak, slid open. Nick reached for a sword that was not there and was glad to see Alan. He was also glad to see that Alan had his sword.

Alan smiled, laugh lines leaping out from the corners of his eyes. “I see you’re feeling better.” He threw Nick a little heap of fabric, which Nick unfolded and saw was a shirt, the crisp buttoned kind you should wear with a suit. He was about to refuse it when he glanced down at his T-shirt and saw that it was stained with vomit and blood. He didn’t want to know if he’d hacked up blood. He just changed shirts.

Once he had done so, he gestured around at the room. “All this is very posh.”

“It’s Merris Cromwell’s house.”

Nick supposed that made sense. Everybody knew Merris had money, even though he hadn’t known she had this much.

“Where are the others?”

Alan looked pleased that he’d asked. “Nearby. Mum’s asleep, Merris gave her something to calm her down, but the others are wondering how you are. We’ve all been put in the north wing, so we’re pretty close to {ret dogether. Do you want to go see them?”

Nick shrugged, and Alan led the way. The north wing seemed to be mostly corridors so wide they almost qualified as rooms, the walls sleek and white and the wooden floors all dark from years and polish. They found Mae and Jamie in a room reminiscent of Nick’s, with the same solemn-looking bed and crenulated ceiling. Jamie was sitting cross-legged on the bed, and Mae was pacing across a fluffy white rug that looked like a decapitated polar bear.

“We should go check on him,” she said as Nick opened the door.

Jamie nodded in his direction. “I think he’s probably all right.”

Mae looked around and did not blush. Nick liked that, the way she felt no need to pretend either indifference or exaggerated concern. She just nodded at him.

He was not used to big houses like this. He was used to small, shabby houses and flats, places with so few rooms and such thin walls that he always knew where Alan was. Now he was in wide open spaces under vaulted ceilings, and he was noticing too many things about this girl. The strangeness of it all made him feel irritated and uncomfortable. He slouched against the wall and looked deliberately through Mae. After a few moments she moved away from the coldness of his fixed gaze, toward Alan.

It didn’t make Nick feel any better. He felt restless suddenly, and as he tuned out the others’ voices and wished for something to do, he registered again the sound that had woken him. Coming to him through heavy doors and solid walls, through all the expensive privacy of this house, were faint but unmistakable screams.

It was obvious that the rest of them couldn’t hear it. He should probably tell Alan.

“There is someone being tortured in this house.”

Alan gave a guilty start, and it was clear to Nick that he at least already knew.

“That’s not entirely true,” he said hastily.

“Tortured?” exclaimed Jamie.

Nick shrugged. “Sounds like that to me.”

“Alan,” Mae said, in a tone of command rather than appeal. “Where are we?”

Alan looked defeated already, as if some terrible fate was rushing upon them, something as impossible to reason with or escape from as a storm spilling darkness across the sky.

“This is the House of Mezentius,” he said.

“That’s what it said above the door,” Nick agreed. “Who’s Mezentius?”

Alan seemed to be having trouble with the words. “He was an Etruscan king in a legend,” he said slowly. “He had living people bound face-to-face with dead bodies and left to starve.”

“He sounds a charming host,” said Nick. “I thought you said this was Merris Cromwell’s house.”

“Merris runs the house,” Alan answered in a low voice. “It’s her job to organize everything here, to keep everything…contained.”

“Well she’s not doing a very good job, is she?” Jamie exclaimed. “If there’s someone being tortured in here.”

“That person’s here of their own free will,” Alan told him.

His eyes looked more bruised and sad with every word dragged out of him, and Nick felt the impulse to silence all the questions that were hurting his brother. He’d always trusted Alan to know best, trusted that Alan would sooner or later tell Nick everything he needed to know. He thought of that hidden picture, though, and about him letting that magician go. There were some things Alan never said anything about. He wondered what secret Alan was hiding this time.

He kept quiet, and let Mae and Jamie keep pushing for answers.

“Do you know the person who’s screaming?”

“Why would someone come here to be tortured?”

Mae demanded, “Can’t you just show us what’s going on?”

Alan looked almost gray. “I can,” he said. “But you don’t want to see. I swear, you don’t want to see.”

There was another slight movement of unease in Nick’s gut. He could still shut them both up.

He hesitated a second too long and gave Mae the chance to make up her own mind.

“Let me decide that for myself. I want to see.”

Alan walked down the staircase heavily, as if he was carrying a large burden that he did not expect to be able to put down for some time. Mae walked with a firm step beside him, Jamie was hanging back, and Nick became more and more convinced that he did not like this place.

The staircase was wide, a gleaming marble flight of the kind that women swept down in the sappy movies Alan liked. Only instead of leading to a ballroom, it ended in a hall with the same dark polished floors and severe white walls as the corridors in the north wing. Nick kept trying to work out why this place jarred on him so much, and then he got it. The north wing with its four-poster beds and fancy ceilings was a disguise, and this house was as much of a facade as the decorative gate outside.

This was not a stately home. This place was an institution.

The screaming was getting closer.

After a moment’s analysis, Nick decided that it was just one person screaming. It was a woman, and she sounded young, or at least not old. The hall opened into more corridors as they went along, and Nick was amazed that he had not realized before how clinical the corridors were, perfectly upkept, with no pictures or even creaking old radiators to lend them personality. They passed a few simple wooden doors, but Alan kept going, and their little group silently followed him.

Everyone could hear the screams now.

They turned a corner in the winding passageways, and the screams suddenly had a definite location. They were coming from a large metal door down the corridor, on the left. There were no other curves remaining in the corridor, and Nick saw it stretching on into dimness. Glinting at intervals in the dimness were other metallic doors, armored so they bulged out of their door frames, looking forbidding and utterly out of place.

As they drew level with the first metallic door, the screaming stopped.

The scream was cut off so abruptly Nick thought that the person screaming must have died. There was a small window in the door, though, wire forming tiny squares inside two sheets of glass, and when they peered inside they saw no dead bodies.

There were two people in the room. There was a woman kneeling on the floor, and there was a man chained to a wall.

Nick’s first reaction was disbelief. This house might be an institution, but it was clearly civilized and organized. It seemed unbelievable that these quiet corridors could lead to dungeons.

Then he looked at the prisoner properly.

At first sight he was a normal man. His face was deeply lined and his body was stooped in his chains, so he looked old even though most of his hair was brown. He wore old clothes, and a beard covered most of his face.

As they all stood staring, the man’s flat black eyes darted toward the window in the door. His expression did not change.

His eyes did. They bulged in his eye sockets, bulged until they seemed to bulge out of his eye sockets, and then Nick realized they were not bulging at all. The man’s eyes had seemed almost like normal eyes at first, but now the pupils expanded as if someone had tipped ink into two saucers and filled them from edge to edge with shiny black.

The black ovals that had been his eyes were lifting themselves out of his eye sockets, showing little legs, and in the space of a few seconds there was a fat black beetle emerging from each socket. They crawled down the man’s face like tears.

Jamie screamed, the sound shuddering into a moan, and there was movement in the corner of Nick’s eye that suggested he and Mae were clinging to each other. At Nick’s side he could feel Alan trembling. Nick was distantly aware that he should be shocked himself, but he’d seen a lot of things in his life worse than this. He kept watching with calm interest, and the man’s face sharpened as if he was a dog who had caught a scent. There was a long moment where Nick was sure that somehow the man could see him.

The man winked, his wrinkled eyelid flicking over the raw hollow of his eye socket. Nick hesitated for a second, and then winked back.

One of the fat black beetles reached the man’s chin and dropped into the kneeling woman’s hair. She looked up and shook the beetle onto the floor with a convulsive tremor, but aside from that initial movement of automatic disgust, she did not seem surprised. She looked to be in her mid-twenties, with thick chestnut hair and brimming eyes. Nick wondered what had made her scream.

“I see you’ve met Ruth and Thomas,” said Merris Cromwell, her voice ringing clear and calm against the corridor walls. She spoke as if she was introducing people at a cocktail party.

“Met Ruth and—? What the hell is wrong with that man?” Jamie demanded, his voice unusually ferocious. He strode toward Merris, and Nick noticed that his shoulders were shaking. He imagined from the way Jamie was behaving that he already knew what was wrong with the man and was doing his best not to believe what he knew.

Merris walked down the corridor as if she could not see Jamie, and at the last moment before a collision was inevitable Jamie stepped aside. “Let me see,” she said. “Mute, with no trace of his former personality remaining, and with the ability to manipulate anything in the natural world, including his own body. I shall take a wild leap and say that he’s possessed.”