The patio doors slid open, and a new creature appeared. This was a tall, thin, mantis-like being, bright green in colour, with clawed forelimbs and a triangular head with three eyes. It was wearing a pink dress and pearls, and had blonde hair cut in a bob.

"Harry, darling!" it called out. "It's almost suppertime!"

Harry sighed theatrically. "Coming, Mom."

Luca relaxed a little. If that were Harry's mother, then she probably wasn't any threat to them. Although it did make him wonder what the boy's father was like.

Harry paddled to the side of the pool and climbed out, while his mother examined their two guests who were still in the water. Alberto and Luca grinned nervously at her.

"Who are your friends?" Mrs. Waternoose asked her son.

"This is Alberto and Luca, from school," Harry replied. "This is my Mom, Edith."

"Nice to meet you, Madame," said Luca.

"Darse..." Alberto began, then glanced at Luca, remembered how embarrassed they'd been when they learned what what's wrong with you, stupido? actually meant, and cleared his throat. "Hi."

"Will you two be staying for dinner?" Mrs. Waternoose asked politely.

"Of course they will," said Harry.

"That's wonderful." She smiled at them, showing off what appeared to be at least two rows of sharp teeth. "We're having fish tonight."

"We like fish!" said Alberto.

"Yes, very much," Luca agreed.

They climbed out of the pool and grabbed their clothes to follow Harry inside. His mother had given him a towel to drape around his shoulders, but there were none for Luca and Alberto. They were dripping as they crossed the threshold and left wet footprints on the carpet inside.

"Oh..." Mrs. Waternoose began, looking at the mess.

"Sorry," said Luca.

"We're sea monsters. We have to stay wet," said Alberto.

She hesitated, then apparently accepted that. "Oh," she repeated.

"I'm gonna go get dressed," said Harry, and scuttled up a flight of spiral stairs.

Mrs. Waternoose smiled at her guests again, and Luca and Alberto tried to smile back without looking too intimidated. Her height and resemblance to a mantis made Luca very nervous, unable to escape the feeling that she was about to snatch him up and devour him.

"Are you two new at Harry's school?" she asked.

"Yes, Madame," said Luca.

"We're from Milano," Alberto added.

"Well, it's very nice of you to make friends with Harry," Mrs. Waternoose told them. "He doesn't really get along well with his peers and he's often very lonely."

Luca and Alberto were beginning to get an idea why that might be, but didn't want to say so in front of his mother. "He did look like he needed a friend," Luca said awkwardly.

Alberto put an arm around Luca's shoulders. "I got Luca out of his shell," he said confidently. "I'm sure we can do the same for Harry."

"How lovely. Now," Edith Waternoose added, "just to warn you. I don't know what Harry might have told you about his father, but Hank can be rather gruff and I don't think he had a very good day at work today. Don't let him get to you. He wants Harry to have friends, too."

"Yes, Madame," Luca repeated.

"Right this way," she said.

Mrs. Waternoose led the way through the maze of the house, down a long hallway lined with elegant paintings and framed newspaper articles about the success of the Waternoose family and their company. When they came to the stalk-eyed maid vacuuming the carpet, Mrs. Waternoose simply climbed the wall like a spider and went around her. Luca and Alberto excused themselves and squeezed by as best they could with their feet on the floor.

The family's dining room looked out onto the gardens, with large multi-pane windows down one side and matching mirrors on the opposite walls. In between was a very long, narrow table with many chairs on each side. Mrs. Waternoose seated herself at one end of the table, while Schrecklich the butler came to pull out chairs for Luca and Alberto right in the middle of one side. Another servant poured them each a glass of water.

"Thank you," said Luca.

Alberto poured his glass over his head. Luca did likewise. The servant stiffened in surprise, but instead of telling them off, it looked at Mrs. Waternoose for guidance.

"They say they have to stay wet," she explained. "You can clean it up later."

Luca smiled apologetically. "Sorry about the carpet," he said. At least it was just water, and nothing that would be too difficult to clean up.

The servant nodded and left the room again. Uncomfortable silence descended.

A couple of minutes later, Harry arrived, wearing a little jacket and necktie as if to have his picture taken. The butler seated him opposite Luca and Alberto and he was given a glass of water of his own. He did not thank either servant, or say anything to his mother.

Luca kicked his feet under the table and looked around the room for something to think about and distract himself from how awkward it all was. In between the mirrors and windows were imposing portraits of various monsters, some with too many limbs or eyes, others with mismatched body parts, like lobster claws or tentacles or antlers. At intervals down the long table were crystal vases of odd-looking flowers. The petals were green on the outside and pink on the inside, with spiky white rims. Luca wondered if they might be a kind of orchid, but then a fly landed on the table next to one vase. The flower immediately bent down and snapped it up, chewing a couple of times before swallowing and then letting out a soft burp.

Harry snickered, but then quietly quieted himself when he met his mother's disapproving eye.

"I thought I told the gardener to teach those plants some manners," she said with a frown.

Luca swallowed. This was a very strange world they found themselves in, indeed.

Suddenly, Mrs. Waternoose and her son both sat up straight and turned to look at the far door. A moment later, Luca heard the sound of something approaching – something with many, many large, heavy feet. As it got closer, the plates and cutlery rattled, and the flowers in the vases closed their mouths and covered themselves with their green leaves. Alberto and Luca inched closer to each other, and leaned forward a little to see what was about to arrive.

The far door opened.

There were three entrances to the dining room. There was the ordinary, if very high-framed, doorway that Mrs. Waternoose had led the boys in through, and which Harry had arrived by. A smaller one, with a door that shut, was at the end of one of the long walls. This was the one the servants came and went by. The third was at least three metres high, with dark wooden doors under an arched top. All eyes were on it as the doors swung into the room, and the yawning opening admitted a beast that matched it in scale.

"Good evening, dear," said Mrs. Waternoose. It was almost a question.

"Hi, Dad," said Harry.

Luca's throat had gone so dry, he had to check and make sure he hadn't Changed. Words didn't want to come out, but he managed to squeak, "Sir."

"Hello," said Alberto.

Henry J. Waternoose the Second was enormous. Like his son he was predominantly grey in colour, with thick skin like the rhinoceros Luca had seen in one of Giulia's books. Where Harry had multiple eyes like his mother, Mr. Waternoose had only two big, bulbous pink ones with no pupils, set above a mouth with boar-like tusks pointing up at the corners. He had six segmented legs like Harry's, but his body ended in a tail like a scorpion's, with a nasty-looking sting at the end. He was dressed in a black jacket and a cream silk ascot, with a glittering pink gem in it that matched his eyes.

The child who saw that come out of their closet, Luca thought, might never sleep again.

The servants pulled up a huge chair, specially designed for Waternoose's long body, and the family patriarch settled down on it. Both servants, plus Schrecklich the butler, were required to push him in.

It was impossible to tell where Mr. Waternoose was looking, which just made Luca feel like he was being watched very closely indeed. He sat up straighter, and tried very hard to keep his legs still. Hopefully, Waternoose wasn't actually staring straight at him, and he could...

"Who are they?" Waternoose growled, pointing a clawed them at Luca and Alberto.

"Harry's friends from school," Edith Waternoose replied. "Be nice."

Now Waternoose was definitely looking them over. Alberto raised a tentative hand.

"Alberto Scorfano," he said.

"Luca Paguro," Luca chimed in.

"Immigrants," grumbled Waternoose. It was difficult to tell if he disapproved, or if that were just how he always sounded. "What are you planning to do when you grow up?"

"I'm going to be a fisherman, like my dad," Alberto replied. Luca expected him to add that he was amazing at it, but he did not.

"I haven't decided yet, Sir," said Luca, "but maybe I'll be a teacher." He liked the idea of bringing the wide world beyond Portorosso to the other sheltered sea monster kids at home.

Waternoose nodded slowly. "Figures. Neither of you could frighten a rabbit. This new generation," he said sourly, as one of the servants poured him a glass of champagne. "Some of them are downright cuddly. Barely worthy to be called monsters at all."

"You're terrifying, Sir," said Luca. He had no idea if that were the polite thing to say under the circumstances, but it was entirely honest.

"I know," Mr. Waternoose replied, grim.

Luca didn't dare say another word after that. A servant who resembled a walking tree arrived, and passed out plates of fish that had been cooked whole with their heads still on. Luca knew humans did that for fancy occasions, so he wasn't too startled by it, but he still didn't like it. On the farm any fish they ate would be ones they'd raised themselves, and Luca's parents knew he didn't like looking at their dead faces and remembering their names. These fish, of course, were strangers, but they each had three eyes, which did not help.

The Waternooses picked up their cutlery and began to eat. Luca decided he would cut up his fish and at least pretend, so as not to seem rude. Albert started to reach for his plate with his hands, but Luca kicked him under the table and after an uncomprehending moment Alberto realized that having bad manners here would be a terrible mistake. He picked up his fork and knife and got somewhat clumsily to work.

Luca carefully sliced the head off his fish and pushed it under a leaf of lettuce that had been put on the plate as a garnish. That was better.

Alberto took a bite and apparently didn't find it tasted odd, which made Luca feel a little better. His friend chewed and swallowed, then cleared his throat and looked at Harry. Harry blinked back at him, not sure what Alberto was trying to communicate.

"You were gonna ask your dad," Alberto whispered. "For Michelle, remember?"

Harry shook his head. "I said I'd tell her if he said anything," he whispered back.

"Harry, dear," Mrs. Waternoose said loudly, "is there something you want to say?" She was giving him a disapproving frown.

With a gulp, Harry turned to his father. Before speaking, he stole a glance back at Edith, but found no sympathy. "Uh, Dad? We had to cut our tour of the factory short today..."

The elder Waternoose kept chewing with no reply yet, but fixed his eyes on his son, waiting for the rest of the question.

"Did something happen?" Harry asked. "Because we heard a lot of rumours."

Luca held his breath. Across from him, Alberto chewed slowly, watching Mr. Waternoose with a wary expression.

"Nothing happened," said Waternoose in a low rumble. "Halverson had a fit for no reason. Cost us half a day's revenue."

The boys breathed out, relieved that he hadn't exploded. So did Harry, and for a moment there was silence again. Alberto shoved a big forkful of vegetables into his mouth, and Luca focused on carefully removing every tiny bone from his fish. After a moment, Harry spoke again.

"Has anybody ever actually been killed by a human?" he asked.

Luca and Alberto both looked up from their plates.

"Not on my watch," said Waternoose.

"But somebody must have been at some point," Harry said, "because otherwise how would we find out?"

"It's a well-known fact," his father said.

"What exactly do they do to you?" Harry insisted. "We were talking about this in school today and nobody can agree..."

"Henry Waternoose the Third!"

Harry fell silent, his nerve having failed him.

Waternoose' bulging eyes narrowed as he examined his son. "Was it you who was sneaking around the factory scaring people today?"

"No!" Harry shook his head hard. "It wasn't. I swear, Dad."

"It wasn't," Alberto echoed. "He was with us! If he'd gone anywhere we would definitely have noticed!"

Waternoose settled down a bit. "Good," he grunted.

For what seemed like a very long time, nobody spoke. The silence was so thick, Luca felt as if fish could have swum in it. He poured another glass of water over his head and thanked the tree-like servant for refilling it for him. Waternoose watched this suspiciously, but did not say anything.

"Well!" said Edith, rearranging her own food on her plate. "Today must have been the day for drama, because you would not believe what Peggy said at the Bridge Club! You know how she's the treasurer, well..."

From there on, Luca and Alberto were happy to let the adults talk when they felt like it, and resisted the urge to try to fill the silence when it fell. When Mrs. Waternoose was done complaining about the people she played cards with, she started talking instead about what was going on in the garden society. Apparently, the organizations she belonged to were very political. Mr. Waternoose complained right back, grumbling about everything he was dealing with at work. It made Luca wonder if either of them actually enjoyed anything they did.

Dessert was homemade ice cream with chunks of tropical fruit, which was much more appetizing than the three-eyed fish. Luca tried very hard not to think about whether a world of monsters also might have monster cows. He found ordinary cows to be quite scary enough.

Once he'd cleaned his plate, Mr. Waternoose got up and went off to another room to smoke his pipe and do some paperwork. He did not say goodnight. Mrs. Waternoose handed her half-empty plate to a servant, and then stood.

"Well, I suppose you two have parents waiting for you," she said. It wasn't an order, but the message was clear.

"Yes, Madame," said Luca. She was more right than she knew.

She escorted them to the front door, with Harry following as if he just wanted to say goodbye to his new friends. Outside the sun was setting, with the sky turning orange and the tress casting long, dark shadows across the driveway. Crickets were starting to chirp.

"Thank you for joining us," said Mrs. Waternoose. "I hope Hank didn't frighten you too badly. He's under a lot of stress right now."

"We're fine," Alberto lied. "He's not as scary as he thinks he is."

"Thank you very much for dinner," Luca added.

"You're most welcome! Harry can invite you back at any time." Edith gave her son an encouraging smile.

"I know, Mom," said Harry.

"He can be terribly shy," his mother went on.

"No, I'm not," Harry objected.

"When he was a baby, he didn't want to make eye contact with anybody but his nanny," Mrs. Waternoose continued. "Even his father and I got the cold shoulder sometimes. You got better, though, didn't you, dear? He's still learning to connect with people."

Harry groaned.

"For his first Hallowe'en we dressed him as a little ghost so he wouldn't have to look anybody in the eye! I have pictures if..."

"Mom!" Harry protested.

"Sorry, sweetheart, I'm just trying to help them get to know you," said Edith. "We want them to come back."

Harry grimaced. "I'll see you guys tomorrow," he said.

"Sure will," Alberto replied.

"Thanks again," Luca added.

Edith smiled and waved as she showed them out.

They walked halfway down the long driveway, until they heard the front door shut. Then they took two or three more steps just in case, before dashing into the immaculately-trimmed bushes that lined the pavement. Once they were sure nobody had seen them, they crept back around the side of the house, following instructions Harry had given them earlier. He had promised this would take them to a path that led down the side of the house, where they would pass a garden shed, and then they could round the corner to the servants' door where he would meet them.

By the time they were halfway there, they'd dried out enough to transform back to human. It didn't seem to matter, though, because there were no ground-floor windows on this side of the house. They just kept close to the bushes, intending to quickly dunk themselves in the pool again before knocking on the door. It seemed like a perfectly good plan, until the shed door suddenly opened.

The gardener stepped out. He was a bulky, yellow-brown creature with four arms, too legs, and one eye, wearing a pair of denim overalls and a utility belt full of clippers and spades. The boys froze, but fortunately, this creature wasn't looking at them. His attention was focused on a lawn sprinkler he was tinkering with. They still had time to escape.

Luca tried to run for the bushes, only to bump right into Alberto, who had at the same moment tried to go the other way and hide behind the open shed door. Both of them stumbled backwards. Luca clapped his hands over his own mouth so that he couldn't cry out, but Alberto landed on a bin bag full of dry leaves, which made a loud crunch. The gardener looked up.

That was when the sprinkler suddenly started working again. Water sprayed out, hitting the gardener in the face. He automatically turned it away from himself, right towards Luca and Alberto. The gardener cursed and turned it off, then wiped water off his face and glared at the boys, who were picking themselves up out of wet leaves and grass, sea monsters once again.

"Get out of here!" the gardener ordered. "This is private property! Mr. Waternoose will have your hides hung on the wall!"

The boys didn't doubt it. They fled back into the bushes.

They waited there for some time, while the gardener got the sprinklers set up to spray what they were supposed to spray. For what seemed like far too long, he wandered around inspecting hoses and nozzles, but then he gave a satisfied nod and wandered off to his truck, parked in a hidden place behind a row of lilac bushes, for a smoke.

With this distraction, Luca and Alberto crept back past the shed and into the backyard beyond. Passing through the sprinkler spray kept them damp, and this time they made it to the unobtrusive little door, painted the same colour as the side of the house, hidden down a flight of concrete steps from the patio. Harry was sitting on the bottom step, playing with a yo-yo.

"What took you so long?" he asked them.

"The gardener chased us away," Luca explained.

"We weren't scared of him," Alberto added. "We just didn't want you to get in trouble."

Harry gave a dismissive grunt and put his toy in his pocket, his pre-dinner confidence restored. "Follow me."

The door opened onto a short hallway. Down the end was what must have been the kitchen, if the clanking of dishes and pots and the smells of soap and food were anything to go by. Off to one side was a narrow, dimly-lit flight of stairs that led up to another hallway. This area had bare whitewashed walls and wooden floors, and could hardly have been more difficult from the opulent rooms that Schrecklich had led them through earlier. Luca wondered what this part was for. Did people live here? Maybe the fancy parts were just for show. Some of the furniture had been so ornate, maybe actually using it would damage it.

Harry took them to the second-last door on the right, and peered through the keyhole for a moment before opening the door for Luca and Alberto.

"Here you go," he said. "You can sleep in here, but you'll have to stay quiet because the lock is broken. The bathroom is across the hall. Be careful using it, because it's for everybody."

"Thanks," said Alberto.

The room had two narrow beds in it, positioned with their heads against the wall on either side of the room, and their feet facing the single small window. There were also two night-tables, a dresser, and a chair and a desk, all of them entirely functional with no embellishments at all. Since nobody lived there, the beds didn't even have sheets, only the bare mattresses.

"Now, you promised," Harry reminded them. "You're gonna show me the humans tomorrow."

"Of course," Alberto said. "We're men of our word! Right, Luca?"

"Totally," Luca nodded.

"Good," said Harry, "because if you don't, I'm gonna tell Dad. Good night!"

"Buona notte," Luca said, but Harry had already closed the door, and did not answer. Luca looked around the room, then went and propped the desk chair against the knob, just in case somebody tried to come in. Not that chairs seemed to do very well at keeping monsters out of bedrooms.

Alberto, meanwhile, shook the water off himself like a dog, as was his habit, and then sat down on one of the beds. "This is not what I was picturing," he grumbled.

"Me, either," Luca admitted. When Harry had offered them a place to sleep, he'd imagined a giant canopy bed, like something out of a movie, in a room that would match the rest of this opulent house. "It's more comfortable than Giulia's tree house," he offered – although he, Alberto, and Giulia were planning to sleep over in the tree house at least a couple of times this summer, just because sleeping out there was fun.

"Yeah, but the Pescheria doesn't have any extra rooms," Alberto said. "They've got this entirel palazzo and he put us in the attic."

"I guess if we were in the nice part, we'd be more likely to be found," Luca decided. This did seem like a part of the house where Mr and Mrs Waternoose probably never went. Imagine having places you'd never been in your own house ! Although... Harry still could have offered them some pillows or something. Giulia had given them those and a blanket, even if it had been too hot to use the latter.

"I guess," Alberto echoed, unconvinced.

Luca did see his point. The Waternoose family clearly had far more money than they needed. Why did they even have this part of the house?

Alberto lay down on the bed and wiggled around, trying to get comfortable on the creaky, slightly threadbare mattress. "So when we get back, we can tell Giulia we met a monster scarier than your Mom, at least."

"Yeah," Luca said. "No contest."

"I bet Massimo wouldn't be scared, though," said Alberto.

"No, I'm pretty sure anybody would be scared of Mr. Waternoose." Luca had been waiting until he, too, dried out enough to transform, because he didn't want to get the mattress wet. Now it happened, so he lay down as well and looked at the ceiling. There was a spiderweb in the corner, but even that had nobody living in it. There was a fuzzy layer of dust sticking to the strands.

"Not Massimo," Alberto insisted. "He'd just pull out a harpoon and Waternoose would have to back down. Massimo's not scared of anything."

Sleeping in Rocco's room had not exactly been a fun outing, but it hadn't been at all scary... at least, not until Louise's intrusion. The clock had been a little annoying, and both Luca and Alberto had in the backs of their minds the idea that Rocco could wake up screaming at any moment, but still, they hadn't felt particularly worried about anything.

That night had been interrupted, and it was apparently daytime in this world while it was night in the human one, so the boys had been awake for far longer than they were used to. That should probably have made it easier to sleep, but Luca, at least, was wide awake and terrified.

It was like the worst moments of fearing discovery last summer in Portorosso, with the added problem that the people who might discover them here were far more terrifying than anyone in the little seaside town. Every creak, ever rustle in the bushes outside made Luca jump. Several times he was tempted to get up and creep over to the window or door and see what was the source of some sound, but he didn't dare. He refused to even go to the bathroom, because he didn't want to risk running into a monster who would think he was something dangerous.

It was very strange, really, how these big, powerful, frightening creatures were afraid of humans. Why did they think humans were poisonous, or electric, or whatever it was they thought? Animals that presented those sorts of dangers were usually brightly-coloured as a warning. Luca could remember vividly his mother showing him things like that when he was small – scorpionfish had the iridescent green patches, Portuguese man o'war were bright purple, beaded anemones were red... humans were mostly pink and brown. Sometimes they wore bright colours, but that wasn't the same as being colourful. Maybe the monsters were confused by the clothes? Or maybe because the monsters came in all sorts of colours, they assumed anything dull was toxic.

Alberto, annoyingly but not surprisingly, slept like a log.

Luca woke from fitful sleep around sunrise, and the first thing he realized was that he could no longer wait to go to the bathroom. He swung his legs onto the floor and tiptoed over to the door so he could peek through the keyhole as Harry had done the previous night. The walls here were thin, and he could hear people moving around the house and a few muffled voices, but there was nobody in the hallway as far as that limited view could tell.

"Alberto," he whispered. "Wake up."

"Huh?" Alberto blinked.

"We gotta get wet," said Luca. "We don't know when Harry's gonna come up here and we can't let him see us."

"Right, right." Alberto yawned and stretched, and then they very carefully opened the bedroom door. There was nobody in the hallway, so they darted across and turned the knob on what Harry had indicated as the bathroom.

It was locked. A woman's voice called out, "I'm in here!"

"Sorry, Madame!" Luca replied, as the two of them dashed back into the bedroom and shut the door again.

The bathroom door opened, and boards creaked as somebody entered the hallway. "Hello?" the same voice called out. "Who was that?"

Luca and Alberto put their backs against the bedroom door and braced themselves to hold it closed. Alberto glared at Luca, as if to silently demand why he'd had to open his mouth and let everybody know there was a stranger in the house. Luca could only grimace and shrug in reply It had been automatic, like putting his hand up in school yesterday, and it had worked out about as well.

"Hello?" the woman said again. To their horror, she crossed the hall, and they heard the knob click. Both of them pushed back as hard as they could as she tried to open the door.

After a moment, the woman muttered something under her breath and went back into the bathroom. The door shut, and water ran.

Luca and Alberto breathed out, and Luca grabbed handfuls of hair on the sides of his head and tugged on it, trying to cement the idea that he couldn't just blurt things out.

Eventually, they heard the woman leave the bathroom again. Rather than footsteps, she moved with a creak of floorboards and a series of leathery slapping noises – these faded away as she headed down the stairs.

For a second time, the boys dashed into to the bathroom. This time they made it inside and locked the door, then took turns using the toilet and getting wet. Once satisfied that they looked monstrous enough not to cause a panic, they opened the door to peek out again.

A fleshy limb ripped it the rest of the way open, and they found themselves being glared at from high above by the stalk-eyed maid. Her body was supported by half a dozen tentacles and she would have been quite intimidating if it hadn't been for her frilly apron and cap.

"I knew somebody was up here!" she declared. "You're Harry's little friends! What are you doing here?"

Luca gulped. "We... uh... we..."

"We got lost!" Alberto blurted.

"We got lost!" Luca agreed. "We tried to find our way out of the house but we ended up here!"

The maid was so horrified that a hitherto unseen third eye opened wide in her actual head. "You've been in here all night?"

Luca pointed at the door across the hall. "We slept in there. It was the only one we could get into."

"Don't tell Mr. Waternoose," Alberto added. "The gardener said he'd skin us."

The maid appeared to relax a little, as sympathy took over from shock. "I don't know that he'd skin you, but he wouldn't be very happy. You're actually just upstairs from the exit. This way."

She took them back to the door they'd come in by, and let them out into the yard. "Go around the side," she pointed with one tentacle. "There's no windows there."

"Thank you, Madame," said Luca sheepishly.

"Next time, just ask somebody to show you the say," she told them.

Once she'd shut the door, the boys sat down on the steps and sighed with relief.

"This is way harder than Portorosso," Luca said.

Alberto nodded. "Yeah."