Giulia started to run to the window for a look, but her mother grabbed her and held her back.

"Don't!" Helena exclaimed. "There's broken glass on the floor, and we're all in our bare feet!"

Giulia growled in frustration. "Get dressed, ragazzi," she ordered, pointing a finger at the boys. "We've gotta find him!"

"Where's he gonna go?" Luca asked, as they ran back to their own room to get their things. "He doesn't know where anything is in Genova, and I don't think his kind of monster has that extra sense where they can find their way back to places. The first time we took him through town he was in the pram and could barely see, and the second time he was in the suitcase!"

"He can't even ask anybody for help," Alberto agreed. "Anyone who sees him is going to freak out."

"Then he can't go far!" said Giulia firmly. She opened a dresser drawer and started pulling clothing out. "We'll find him. If he's smart, he'll stick to the roofs."

"I'm not sure he's smart," Alberto said cynically.

Somewhere outside, a dog began to bark. Luca lit up.

"I've got an idea!" he declared.

Helena put her shoes on and set to work cleaning up the remains of the broken window, while the kids got dressed and went straight to the neighbour's home where Helena had dropped off Nerone the dog. Giulia knocked hard on the door and called out.

"Signor Traverso! It's Giulia!"

After a few seconds they heard stumbling footsteps and the bolt slid back. The door cracked open, and Signor Traverso, a tall, skinny man whose face was mostly moustache, blinked down at them. "What on earth are you doing here at this hour?" he asked through a yawn.

"We're here to pick up Nerone!" Giulia replied, as if this were a perfectly normal thing to be doing after midnight. The boys on either side of her nodded.

Signor Traverso blinked sleepily. "What? Now? It's…" he glanced at his wrist, but was not wearing a watch. A moment later, however, a clock somewhere nearby chimed twice. "It's two in the morning."

"Yep! Right now." Giulia nodded and smiled, making it silently clear that she would not explain.

Signor Traverso must have been too tired to argue about it. He shut the door again, and came back a few minutes later with the dog on his lead. Nerone himself was perfectly happy to be awake in the middle of the night, perhaps unsurprising for a creature who spent most of his days napping. He trotted up on his short legs, and greeted Luca and Giulia with happy licks. Alberto, of course, he didn't know as well, but he seemed happy enough that this was another friend of his humans. Perhaps Alberto smelled enough like Luca to satisfy him.

"Thank you, Signor Traverso! We owe you one!" Giulia waved cheerfully as they headed for the stairwell.

"Good ni… good night, Signorina Marcovaldo," the man replied, having to pause in the middle of the sentence for another yawn.

On the next landing, Luca pulled out an object he'd brought with him - Harry's little sailor cap. "Okay, Nerone," he said, offering it to the dog. "Smell this."

Nerone leaned towards it, his shiny black nose twitching as he took in the scent. Then he shook his head and backed away, disgusted.

"Yeah, he knows who that belongs to," said Alberto.

"Can you find him for us?" Giulia asked. "Can you find Harry?"

They made to continue down the stairs, and Nerone seemed to get the idea quickly. He began straining at his leash to run ahead, bouncing eagerly down the steps towards the street with his hindquarters sometimes nearly trying to overtake his head on the way. The kids ran to follow him, and he led them back to the street and uphill to the building where Giulia and her mother lived.

The apartments were built around a little courtyard that resembled a medieval cloister, though much smaller, with a covered walkway bordering an open rectangle with potted plants and a tiny fountain. The window in the bathroom looked out over this, which meant that after breaking it, Harry would have climbed out onto the walkway roof, and from there would have been able to drop to ground level. It was easy to spot the broken window. Helena had the light on as she finished cleaning up.

They led the dog to the most likely place where Harry would have landed, and directed him to sniff the ground. Nerone was willing enough to do so, turning in a circle with his nose to the ground and his tail perked up. Whatever he smelled, he didn't seem to like it, and made the same disgusted face as he had at Harry's hat.

"Yes, that's right!" Luca urged. "Now, follow him!"

Nerone started sniffing at one of the potted plants. The kids watched him, waiting for him to do something, but he took his time, moving from one plant to another and stopping to pee on one of the pots.

"What's taking him so long?" Alberto complained.

Helena's face appeared in the window above them. "What are you doing?" she asked.

"We're trying to get Nerone to track him by smell," Luca explained. "Like in the movies."

Helena frowned. "You… you do know that those dogs have to be specially trained for that, right?"

Luca had not, in fact, known that. He looked at his friends to see what they thought. It was pretty clear they were surprised, too.

"Nerone's barely trained to wait five minutes while I open a can of dog food," said Helena.

"Oh." Luca's shoulders slumped. "Sorry," he said, embarrassed. "I thought that was a good idea."

"It sounded like a good idea," Giulia agreed, and grimaced as the sound of more barking came from elsewhere in the city. "The dogs are really upset tonight. It's…" her eyes widened. "Of course!"

Luca had the same thought at the same time. "Nerone doesn't like Harry! Neither did the gelato man's dog!"

"Come on!" said Alberto.

Helena lived in the San Teodoro district. The sound of barking was coming from the south, closer to the harbour. The kids ran through the narrow, twisting streets. Because Genova was so much bigger than Portorosso and the people there worked at less demanding jobs, it had a nightlife that the smaller town lacked. There were a surprising number of people out and about, even as 'late' turned into 'early'. People and cars were in the streets, and the windows were bright in bars and dance clubs.

Nerone didn't know what was going on and certainly had never understood that the kids wanted help finding a missing monster, but he did know they were going for a run and that was one of his favourite things. Furthermore, they were running towards other dogs who were barking up a storm, and that was something he definitely wanted to be apart of. He sprinted along with his tongue hanging out of his mouth, letting out an occasional yap of his own to let the others know he was on his way.

"What is their problem tonight?" a woman asked, as the group ran past a restaurant entrance.

"No idea," said one of the friends with her, lighting a cigarette. "They're sure excited about something."

Nerone barked again as they got closer, and then, from up ahead, they heard a scream.

The kids had been getting tired at this point, but now they found a second wind as they sprinted the last few metres to turn the corner into the piazza in front of San Francesco da Paola. Several dogs were barking at something wrong the buildings, and one unfortunate man who'd been taking his spinone for a late-night walk was holding on to the leash with both hands as it tried to get free to bark at Harry, who was standing in front of the metal doors of the church with his arms crossed over his chest.

"What in god's name are you?" the man with the dog demanded.

"I'm a monster!" snapped Harry, annoyed. "Now, take me to the train station, and I won't hurt you!"

"What are you going to do?" asked the man, "gnaw my ankles?"

Harry responded by hissing and scurrying towards him with his arms held up. The man yelped in terror and ran, dragging his dog behind him even as the animal continued to bark.

"Chicken!" Harry shouted after him.

The kids came running up. Harry looked towards the sound of people approaching, then yelped as he realized these ones were likely to trap him in a suitcase again. He turned to run, but Nerone bit into one of his many legs, prompting a pained screech from Harry, and the boys grabbed his arms while Giulia got the dog off him.

"What do you think you're doing?" asked Alberto.

"Going home!" snapped Harry. "You can't tell me what to do. Neither can any of these humans - they're all too scared to do anything. Ercole was too scared to even tell me not to sleep in his room. He would do anything I told him to! He needed you guys to take me away for him!" he huffed, and then stood up straighter. "These humans are so easy to scare I don't know why my Dad even bothers with the door thing. We could just come right in and scare them all, and they wouldn't dare do anything about it!"

"Yes, they will," Luca insisted.

"They totally will," Alberto agreed.

The bronze doors of the church of San Francesco da Paola and the adjoining mendicant monastery had been closed for the night. Now they opened a crack and a monk in his dark habit stuck his head out. "What is going on out here?" he asked. "You children should be in bed, not roaming the streets."

"Shut up!" Harry said, and spun around to snarl at the man.

The monk stared, then made the sign of the cross and slammed the door again.

"See?" Harry turned back to the other kids. "Just because you're not scary enough to make them do what you want…" he began.

Then they heard a renewal of barking. A light came on in a building across the piazza, and a voice shouted, "in front of San Francesco!"

"Come on!" Alberto tugged on Harry's arm. "We gotta go!"

"No!" snarled Harry. "Watch - they'll do whatever I want!"

The man with the spinone appeared around the corner again, his shaggy black and grey dog barking excitedly as it pointed its nose towards Harry. "There!" he shouted.

A policeman was the next to step out, and by he light of the streetlamps the kids could see a half-a-dozen other people behind him, men and women both. Some of these gasped at the sight of Harry, while one woman exclaimed, "my God! What is it?"

The policeman put his whistle in his mouth and blew it to summon help. "You kids!" the policeman pointed. "Get away from that thing!"

"Wait!" Luca held up his hands. "We can explain!"

Harry pushed past him. "Everybody!" he addressed the gathered humans. "My name is Harry Waternoose and I'm…"

The policeman stepped forward and kicked Harry in the face.

This was a shock to the kids, but to nobody moreso than Harry himself, who staggered backwards with his hands over his bloodied nose. "Who do you think you…" he began, then had to duck as the policeman swung at him again.

Behind him, the doors of San Francesco opened again, and half a dozen monks came out, carrying bibles, crosses, and censures - and two carrying the tall metal candelabras that were used to light the church for night services. These were over six feet tall and well able to be used as weapons. The abbot, marked out by his broad black hat, strode towards Harry with a cross held out, repeating a prayer.

Harry didn't know what any of that meant. He backed away from it, but that brought him closer to the policeman, who had his truncheon out. Two more police, another man and a woman, had arrived, and various other people were gathering with improvised weapons. He looked around. The piazza was shaped like a triangle, with the wide end towards the north. There was another road there, leading uphill - the one Luca, Alberto, and Giulia had come down. Harry started to head towards them, but then there was another chorus of barking dogs.

The kids looked back. Another policeman was coming from that way, with a couple more people behind him. There was now only one way to go, and that was south, where a brick path wound its way down a very steep hill towards the harbour.

Giulia knew Genova well enough to know, however, that the winding road wasn't the only way down. She rolled up her sleeves, transferring Nerone's leash from hand to hand as she did.

By now it had gotten through to Harry that he was in terrible trouble. He hunkered down in the middle of the piazza and covered his head as people got closer.

"Don't hurt me!" he begged. "I'm sorry! Don't hurt me!"

"Grab him and then follow me," Giulia ordered, and took off for the path.

The boys dived on Harry. Alberto took the monster boy's left arm and Luca his right, and then they just kept going, dragging him past the startled and shouting people and the policeman ordering them to stop. They followed Giulia as she passed by the gates of the walled garden at the south end of the monastery and rounded the corner. The path continued there, turning right to hug the side of the steep hill, but Giulia didn't go that way. Instead, she and Nerone ran up to a green wooden door in the wall on the left side. Giulia threw herself against this and it burst open, revealing a steep dirt track that went directly down through the trees, bypassing the winding road.

The boys dashed through, Harry scuttling as hard as he could to keep up with them, and Giulia slammed the gate behind them. The path was not an easy one for people in a hurry, and the group ended up doing more sliding than running. The main route went right, to join back up at the road with another door, but Giulia turned left and went through the trees. This wasn't much easier, but at least by holding on to branches and shrubs they could keep from falling down.

The trail brought them between a pair of apartment buildings and into a small garden, divided from the road by a tall fence. Alberto, Luca, and Harry climbed over, and Giulia hefted the dog over the top for Alberto to catch. Then she scaled it like a lizard on a wall and jumped down the other side, and all of them, including Nerone, were able to stop and catch their breath.

"We can't stay too long," Giulia cautioned. "They'll figure out where we went eventually."

The sound of voices shouting and more barking dogs told the boys that she was right, but they spent a few more moments leaning on the fence, breathing hard and trying to swallow the metallic taste of exertion in their mouths. Harry was in the worst shape of all, holding on to the fence with both hands as he panted.

"They weren't afraid of me," he whimpered finally.

Giulia rolled her eyes, but then she reached out and patted his back. "Yes, they were," she said. "That was the problem – they were scared to death. When humans are scared of something and it's just one or two of us, we run away, but when there's more, we get together to hurt it before it can hurt us.

Luca nodded. "That's what happened to us, too. We got rained on in front of the whole town, and if it hadn't been for Giulia and her dad I dunno what would have happened."

"Yeah, we never even threatened them or anything," Alberto agreed. "Unlike some people."

"What did Giulia and her dad do?" asked Harry. "Did they fight them?" He looked both hopeful that this was the case and skeptical that it could be.

"No," said Luca at once. "They just reminded everybody that we'd been there all along and never tried to hurt them."

"Although Massimo would have fought them all if he had to!" Alberto said proudly.

"So why didn't you just tell all those humans I wouldn't hurt them?" Harry asked.

"They wouldn't have listened. They don't know us," Giulia pointed out. "Everybody in Portorosso listens to my dad because they've known him forever. Genova is too big for that. Nobody here even knows about Luca, except for the teachers and a couple of friends we really trust."

"Remember Dorotea and her mom?" asked Luca. "They don't even know."

"Also, you actually were threatening to hurt people," Alberto reminded Harry.

Harry hung his head. "No wonder Dad doesn't want humans to know about us."

That was a sobering thought. If the parents of the world knew that there really were monsters in their children's closets, they would probably camp there waiting for them, just like Luca and Alberto had in Rocco's room… except that the parents would bring harpoons or even guns and that would make everything so much worse. None of the kids had been born yet when the War had happened, but all had heard the way the adults talked about it. Even the sea monsters, who weren't involved, had been affected by the warships and submarines. Nobody wanted anything like that to ever happen again, and a war across two worlds, between humans and monsters who really had nothing to fight about besides that each found the other frightening, would be both terrible and pointless.

"I wanna go home," Harry complained.

"Like… home home?" Luca asked cautiously. "Back to your world?"

"Yeah," Harry said.

Giulia stood up and brushed off her hands on the seat of her shorts. "Let's go, then."

There were several close calls as they crept through the narrow streets of the city back up the hill towards Helena's apartment. Fortunately, Genova was a positive maze of winding medieval streets, and every time they were almost caught, they were able to find a trash bin or a side street where they could crouch in the shadows until danger had passed.

They arrived to find Helena, still in her nightgown and slippers, pacing anxiously in front of the entrance to her building. A man across the street came out the door of his cafe to leave the garbage for pickup, and spared a worried glance for her, but seemed to decide not to intervene. He brushed his hands off and went back inside, locking the door behind him.

Once he was out of sight, the kids hurried out to meet Giulia's mother, who greeted them all with hugs – even Harry.

"What were you thinking," she asked him, as she got a hold of the rambunctious dog. Nerone was wagging his tail, not knowing anything about what had just happened except that it had been an unexpected adventure.

Harry didn't answer.

"Hes' fine," said Giulia. "He says he wants to go home now."

Harry nodded miserably, and Helena patted his shoulder.

"I hope you've learned an important lesson, young… monster," she said.

"Yes, Ma'am," he replied, cowed.

Upstairs, Helena had cleaned the bathroom floor and taped some plastic up over the window so that the birds and insects couldn't come inside, so there was nothing more to do but send everybody back to bed. Nobody said very much, although Luca did wonder what would happen if Harry tried to escape again. He probably wouldn't, but what if his change in demeanour was just an act?

It seemed he needn't have worried, though. Come morning, Harry was still there, and was still very quiet as he ate his breakfast. They did not discuss what had happened last night. Once the meal was finished, Luca and Alberto helped clean up the dishes, while Giulia and her mother packed up the things they would need for their ruse.

They had decided it would look best if the kids wore school uniforms. Alberto borrowed one of Luca's, choosing the short-sleeved jacket so it wouldn't be obvious that his arms were a little too long for it. It was a bit narrow across the chest, too, restricting his movement, but the part he really didn't like was the necktie.

"You really have to wear this every day?" he grumbled, tugging at it.

"You get used to it," Luca assured him.

"All right," said Helena. She was in work clothes – a pair of paint-spattered overalls and a man's striped shirt, with her hair tied back under a kerchief. "Is everybody ready?"

"Yes, Ma'am," said Luca. Harry just nodded.

"Let me do the talking," Helena told them. She unzipped the suitcase for Harry to climb in. "Unless somebody asks you something directly, and even then you can just say you don't want to talk to strangers if that'll help. I'm the one who knows the people in there."

The kids agreed. Harry curled up inside the suitcase without complaint this time, and they trundled their way down the hill and around the harbour to the Palazzo Spinola. Luca had read about this place in a newspaper, and couldn't resist the urge to talk about what he'd learned to his friends as they wound through the tangle of increasingly dim and claustrophobic streets in the old city centre.

"The building is almost four hundred years old," he told Alberto. "Like Singora Marcovaldo said, it used to have a third floor, but that got bombed during the war."

Alberto frowned. "How did they bomb the third floor without getting the ones under it, too?"

"I dunno," said Luca. "A few years ago, the owners gave the whole thing to the city, along with all the paintings and furniture in it. It used to be somebody's house, so that somebody probably would have had kids and it makes sense that the monsters would have portals into their closets."

"Not so loud!" Giulia said, as a woman passed them with a dog on a leash. The dog sniffed at the suitcase, its ears back, but its owner hurried it along.

"Sorry," Luca said. He leaned down a bit to whisper to the suitcase. "You okay, Harry?"

"Yeah, I'm good," Harry muttered. "Are we almost there yet?"

"Almost," said Helena.

The main facade of the palace was on the Piazza di Pellicceria, which was a wide-open public space by the standards of the cramped medieval part of Genova, but tiny to people used to the Piazza Calvino in Portorosso. The main entrance was boarded up and covered with scaffolding for the restoration work, so Helena walked right past it and around the side, to yet another very narrow and dark alleyway that reminded Luca and Alberto of an underwater trench. Buildings rose up like cliffs on either side, and only a few thin shafts of sunshine managed to make their way down through the forest of roofs and chimneys above.

Here was a door with a sign on it that said Avviso: Solo Personale Autorizzato, and a bored-looking security guard standing next to it doing a newspaper puzzle. He looked up and smiled.

"Buongiorno, Signora Marcovaldo," he said. "I didn't know you were going to be here today."

"I called ahead to management," Helena replied. "Signor Zaccaria said I could bring my daughter and her school friends. They're supposed to get pictures of a historical landmark this summer, and they're very excited to see one that nobody else can get into."

The kids did their best to look enthusiastic.

"Well, be careful," the guard warned them. "Don't touch anything. There's a lot of damage in there – and one of the upstairs rooms is supposed to be haunted!" He winked.

"That's great!" said Alberto.

"Yeah! Imagine if we get to show the class a real ghost!" Giulia clutched her camera.

"They're prepared," Helena told the guard.

The man unlocked the door for them, and they headed inside.

The outside of the Palazzo was fairly drab. Some of the fancy plasterwork had survived the war, but especially around the sides and back there was little to distinguish it from the humbler buildings nearby. Inside, the first floor was being used to store building supplies and old furniture covered in cloth. They passed that by and went up the first flight of stairs.

The second floor had been the Spinola family's living area at the height of their wealth. It was now dusty and mostly unfurnished, with broken mirrors and missing light fixtures, and in one large room the entire frescoed ceiling had fallen down. People were laying out the bits of plaster on a drop cloth to reassemble the image like a jigsaw puzzle. Yet for all the ruin, it was clear that this building had once been magnificent. There were fancy tiles and marble mosaics on the floor, dozens of hooks on the ways for hanging giant mirrors and paintings, and places for fancy lights and chandeliers. What was left was almost nothing like the old black and white photographs from the newspaper, and yet Luca could see where that grandeur had once been.

Giulia was impressed, too. She raised her camera and began taking pictures.

"This looks like Harry's place after a tidal wave hit it," was Alberto's assessment.

"The haunted one is supposed to be the green room," said Helena. "It should be through here."

Like many of the grander buildings in the city, the palazzo was arranged around a small central courtyard, one room leading into another rather than wasting space by having them branch off a hallway. That made it easy to get confused as they seemed to turn corner after corner, but Helena knew where she was going and brought them to a room where the walls were a bright spring green. Much of the paint had now come away from the walls during the bombing, along with the plaster underneath, leaving bare brick walls. What little remained was mostly in the corners and along the street-facing wall. There was no furniture and, more importantly, no sign of a closet.

"Is this it?" asked Alberto, opening the door opposite to the one they'd come in by. This, however, only brought him to the next room over, which had half the floor taken up to replace some damaged joists. The workmen looked up in surprise at this unexpected intrusion.

"Sorry!" said Alberto, and closed the door again.

"Where is it?" asked Luca, worried.

Helena smiled. "The people who lived in this palazzo were worried about looks, not practicalities. Things like closets had to be hidden. She let Harry out of the suitcase, and then went to a corner and used her fingers to brush dust away from a seam in the paint job. About half a metre away was a ring, and when Helena pulled on that, the hidden door opened to reveal…

… the scaffolding outside. It hadn't been visible from the street, but the outer wall here had partially collapsed, leaving the interior of the closet as a narrow shelf with a wall on the right and the back, and open air on the left.

"Santo Parmigiano!" said Giulia.

Helena quickly closed the door again and looked at Harry. "Ah, does that matter?" she asked.

"Nah," he shook his head. "There's ground in our world, so it's fine."

"Good to know," she decided. "So now we just have to wait."

They made a show of touring the rest of the house, and let the people working there overhear Helena describing the delicate process of restoring things like the broken ceiling fresco. Giulia and Luca pestered the workers with questions, most of which were happily answered, while they left Harry hidden under a cloth in the green room, trying his best to look like a pile of masonry.

At lunch time they had a picnic in the central courtyard, eating sandwiches and drinking lemonade. Then Helena announced it was time to go, and they went around thanking everybody once again, as if they were about to leave. They did not, however, do so. Instead, they went back to the green room and joined Harry in hiding under drop cloths. When the end of the day came, nobody would remember having actually seen them leave, but nor would they remember them being there in the afternoon, and the workers and guards would conclude that their guests must have left hours ago. Nobody would suspect they had any reason to still be hiding inside.

Unfortunately, that meant there was nothing to do in the afternoon but listen to the sounds that echoed inside the building. There were hammering noises from the men replacing the joists next door, and clinks as they began putting the floor tiles back. Voices spoke on the street outside, and at one point somebody tried to bring a dog into the building. The animal must have smelled Harry, because it began barking in a frenzy and had to be dragged back out.

Finally, people began to go home for the evening. The smell of cigarette smoke and the sound of laughter suggested men weren't working as hard as they had been. The door to the next room opened, and the workers from there came through in a cacophony of tramping boots and loud voices. Maybe some of them noticed that there appeared to be objects in the green room that hadn't been there before, but if so, they didn't think it was worth investigating. They went out through the other door, and could be heard descending the stairs.

Even then, it seemed to be forever before Helena became confident that everybody was gone and let them come out from under the cloth. They couldn't turn any lights on for fear of being noticed, so they just sat in the gathering dark and listened to Harry describe what they were likely to find.

"The research labs will have a bunch of door stations," he said. "I've visited them loads of times with Dad." His confidence was starting to return now, as the time came closer to return to his own world. "They'll probably only be using two or three at a time, because they'll be testing different stuff. You know, one will be opened normally, and then another one they'll have done something to."

"They'll have a control group," Luca nodded. Another thing he'd learned about in school.

"There'll be a bunch of scientists," Harry added, "but I'll tell them who I am and that I wanna talk to my father, and it'll be fine. I bet he's looking for me!" This idea seemed to perk him up even more. "I bet there's a big reward out for my safe return. I am his only child, after all."

Alberto wondered… if he'd gone missing, would his father even have bothered to look?"

"Anyway," Harry added, "as long as you guys are wet, it'll…" he stopped, frowning.

"Yeah, we know," Alberto said, rolling his eyes. They'd filled buckets from a sink on the ground floor and were ready to use them. After what had happened last time, they weren't likely to forget.

"No, I think I heard something, too," Luca said, and put a finger to his lips. "Alberto, sssh!"

Alberto fell silent, and there were a series of noises from outside – specifically from the other side of the closet door. The kids moved closer to Helena as a series of thumps, creaks, and grunts came closer and closer. Was there something wrong with the scaffolding, perhaps? Or were the monsters getting to work early?

"Are those the sounds the maids hear?" Giulia whispered.

"I don't know," Helena replied. "I've never heard them myself."

"Should we look?" asked Luca.

Giulia stood up and got her camera ready. "You open it," she said. "If it's something bad, I'll set off the flash."

Luca and Alberto stood on either side of the closet door, water buckets ready, and Harry reached to pull the ring. Helena got behind Giulia, ready to grab her daughter and run.

"Good luck, ragazzi," Helena said.

"Here goes!" Harry announced. He wrenched the door open – only for him, Luca, Alberto, and Giulia all to let out a scream at the sight of something scarier than any eight-metre drop or monster scientist could possibly have been.