As she'd expected, Maria slept badly that night. She left the window open so that she'd be able to hear any uproar that might happen outside, but found herself startled awake by every little sound. Boat engines, branches tapping against the side of the house, barking dogs, all brought her sharply back to full, panicked wakefulness. She thought about getting up and closing it, but then she wouldn't hear anything, even if somebody brought Massimo back on the end of a harpoon.

After what seemed like an eternity of tossing and turning, drifting off only to suddenly wake again, the sun finally rose. Maria dragged herself out of bed feeling like the only thing she wanted to do was crawl back into it.

She'd used to spend lazy mornings with Giancarlo in various hostels as they travelled the Mediterranean coast. If they were in a new place and neither had found work yet, they would lie in bed some mornings until ten or later, talking and cuddling, or just enjoying the luxury of being lazy. Maria no longer had that. Ever since Alberto was born, her life ran on his schedule – and with Helena pregnant and Massimo missing, it now had to run on theirs. Maria had to get up and get ready and go fishing. That meant leaving Alberto with Helena again, which would upset him, and Helena herself was probably not doing well, either.

It wasn't fair, Maria thought, as she stumbled into the bathroom to wake herself up with cold water on her face. She'd almost had a breakdown herself yesterday, but she'd pulled herself back together for Alberto – and then she'd had to keep herself together for Helena. When was Maria allowed to sit down and cry? When would somebody take care of her ?

That was supposed to have been Giancarlo's job, but he hadn't wanted to do it, and there was nobody else.

She washed up and dressed, and then got Alberto ready. Today she wasn't even going to take him outside. She would distract him with breakfast in the kitchen and then slip out while he was eating. It wouldn't have surprised Maria if Helena had stayed in bed, but it seemed that she, too, felt she had to continue doing her daily tasks. She was in the kitchen scrubbing out the pot the neighbour had brought them dinner in, her brow furrowed and her tongue out in concentration.

Maria paused on the stairs for a few moments, watching. If the herb had affected Massimo, maybe as Helena did dishes it would... no, if it had, Helena would have noticed.

"Buongiorno," said Maria.

"Hello," Helena replied, still scrubbing.

"How are you?"

"Pessimo."

Terrible. Maria shouldn't have expected anything different. "I'd better do the fishing," she said. "Ah... I can leave Alberto with the Aragostas, if you'd prefer."

"No, I'll keep an eye on him," sighed Helena. She finally turned around, and Maria saw that her hands were wet and soapy, but had not transformed. "It'll keep me busy."

"Thank you," Maria replied sincerely, and put Alberto in his aunt's arms. "I'll stop in the panetteria for something for myself, and if I hear anything about Massimo I'll come tell you at once."

"As long as nobody else comes to give me news," said Helena, and Maria nodded. News from anybody else was likely to be bad. She wondered suddenly... could sea monsters still transform after they died? What if some fisherman dragged Massimo back to town and left him on the doorstep, only for him to change back in front of everybody's eyes? Would they regret what they'd done, or wish they'd done it sooner? She shuddered.

Helena had noticed, and was giving her a questioning look. Maria did her best to smile. "See you in a few hours," she said.

"See you," said Helena.

Maria got the boat out to where she'd set the nets yesterday afternoon, and began hauling them in. She was distracted as she did so, constantly looking around at the bright dots on the water that represented other, distant fishing boats. Were they just gathering their catches, or were they sitting there with their harpoons poised, waiting for something unknown to pass beneath them?

The net caught on something. Maria looked down and saw an unidentifiable piece of bent metal caught in it. She reached down and pulled it free, only to have it slip from her rubber-gloved hand and fall back into the water. On a reflex, she grabbed for it – she would have liked to take a closer look and figure out exactly what it was before she threw it back – but it was already gone. Her hand went in the sea, and water poured over the cuff of her rubber glove.

"Ow!" she exclaimed, as something pinched sharply inside it. She pulled the gloves off – and then she stopped short and stared.

Her right hand still looked normal – sunburned skin on four fingers and a thumb, and nails she trimmed short because she knew if they got long she would chew on them. The left one, which had been in the water, was completely different. It had only three fingers, each tipped in a dark claw and with webbing between them, like Giancarlo's hands when he was in the water – but it didn't have the deep blue scales his did. Instead, it was ivory on the palm and a coffee-with-cream colour on the back, blotched with chocolate brown spots. Maria turned it over to inspect again, but a rippling sensation passed over it, and it transformed back into a human hand to match her other one.

For a few seconds all Maria could do was sit there in the boat, her heart pounding in her ears. There was a part of her that, even after hearing Albino's story about seeing a sea monster climb out of the water where Massimo had fallen in, hadn't really believed that the herb did what Pinuccia said it would. Now that it apparently had ... she didn't know how to react. She very nearly just returned to pulling the net in like nothing had happened, but then decided she couldn't do that, at least not yet. First... she had to make sure she'd really seen what she thought she had.

Maria raised her head and looked around. She could still see a couple of other boats, but they were a good distance away and she couldn't make out what was happening on board. The fishermen there wouldn't be able to see her either. The anchor was in place. She took a deep breath and, aware that she was perhaps doing something very stupid, dived into the sea.

She'd asked Giancarlo once what it felt like. He'd told her could feel it, but it didn't hurt. The rippling sensation passed over her, and she could feel things like gills opening and narrow bones piercing the skin to become fin rays. Parts of it did hurt, but only in the way getting an injection did – a brief jab, and then it was gone. When she opened her eyes, she was floating a few metres below the surface, with sunbeams streaming down all around her. Behind her was the net full of silvery fish, trailing down to the weights that anchored it to the bottom, and all around her was the shadowy blue of the water.

Where the sun was shining, the surface was transparent and Maria could see the sky. Where the boat cast a shadow was a small area where she could, instead, see her own reflection. She kicked to go closer for a better look.

Squinting back at her was a creature shaped like a human being, with arms and legs in the right places, but with a long fluked tail and with fins framing its face. Its shoulders, arms, and the top of the tail were covered with spots and speckles in shades of brown and a grey that bordered on purple. Where Giancarlo, with his gold, silver, and blue colouration had always reminded Maria of a tuna, her own sea monster form looked like ones of the little catsharks Maria had seen in the waters around the Island sometimes. The sharks had dark eyes, but the ones in the reflection were Maria's familiar green.

Maria stared a few moments longer, then surfaced and grabbed the side of the boat to climb back in. She knew exactly what she had to do now.

She hauled the net in, but did not bother collecting the fish or setting it again. They wouldn't starve to death because they'd missed only one catch. She returned to shore, and was very careful not to get wet as she climbed out of the boat and went up the stairs.

"Signora Scorfano?" asked Dario, as she passed him on the way to the door. "You're back early!"

"I didn't want to stay out too long in case..." she almost said in case there really are sea monsters, but fortunately thought better of it. "In case there was news about Massimo. Is there any?"

"Not yet," Dario said, "but everybody's looking. Signor Castello says if there's any sea monsters out there, they'll find them!"

Maria hurried up the steps and burst into the kitchen. Helena had been working on a charcoal drawing on her easel, and when the door opened she cried out in surprise and accidentally drew a dark stripe all up the page.

"Ma!" exclaimed Alberto, and dropped the toy he'd been playing with to toddle over and throw his arms around her legs again. Maria scooped him up.

"Sorry," she said to Helena, who was staring at her drawing in dismay. "I just... I had to..." she paused, trying to catch her breath. "It's the herb. It got me. I mean... it affected me."

Helena did a double-take, turning to stare at Maria as if she expected to see the Creature from the Black Lagoon. Then she looked at her own charcoal-covered hands, and swallowed hard, before heading over to the sink and turning on the spigot. She gritted her teeth as she stuck her hands in the flow.

"Anything?" Maria asked.

Helena watched the water for a few more seconds, then shook her head. "No," she said, and shut it off again.

Maybe it only affected some people, Maria thought, the way there were people to whom coriandolo tasted nice and people, like Maria herself, who found it tasted like soap. Maybe it didn't work on pregnant women. Perhaps they ought to ask the Aragostas... but Concetta and Pinuccia had already said they didn't know the specifics.

"I think," Maria said, as if this were all entirely ordinary, "I'm going to go up to that little beach we've been using, and take Alberto for a swim. That will keep him happy, and we can look around and see if we can find Massimo."

Maria had no particular plan for this, but she knew she had to try. Wherever Massimo was, he would think he had nobody to turn to. Even if he found other sea monsters, he wouldn't ask them for help, either because he'd be afraid of them or just because he didn't like asking for help from anyone . If anyone were going to find him, it would be Maria.

"If the Aragostas stop by, you can tell them where I've gone," Maria added.

Helena was still facing the sink, staring at the wall above it. Maria couldn't see her face, and had no idea what she might be thinking.

"What if you don't come back?" Helena asked quietly.

"Of course I'll come back," Maria said.

"What if once you're in the water, you don't want to?"

For a moment Maria didn't understand the question. Giancarlo had never seemed reluctant to get out of the water. Alberto came when called, although he wasn't always happy about it. Only half an hour ago, Maria herself had simply climbed back out again. Then she remembered Pinuccia's description of the old story: after eating the herb, the fisherman Glauco had suddely wanted to dive into the sea, where he'd transformed. It hadn't mentioned whether he ever left it again. Maybe he hadn't.

Did Helena think that was why Massimo didn't want to come back? Was she afraid that he didn't want to, or even that he'd forgotten her entirely?

"Even if I don't want to, I promise I will," Maria said. "I promise." She set Alberto down again, and came to put her arms around Helena from behind.

Helena turned around and hugged Maria back, her hands still wet. "I can't do this alone," she said, with tears in her voice.

"You won't be alone," Maria assured her. "You won't. Alberto and I will be back for dinner, and we'll bring Massimo, I promise."

Maria went upstairs and quickly got changed, choosing the lightest sundress she owned. Hopefully it wouldn't weigh her down in the water. Then she got Alberto into a t-shirt and his little swim trunks, which absolutely delighted him. He was wiggling so much she almost couldn't hang on to him.

"That's right, we're going swimming," she said. "And Mamma has a surprise for you! I think you're going to like it."

Young people had been keeping away from the little beach since the sighting of the oarfish, and word that the biggest man in the town had apparently been dragged out to see by a shark creature had not made the place more popular. It was entirely deserted except for a couple of gulls, with foam gathering on the pebbles as the water lapped them. Maria kicked her shoes off and removed her stockings, and then pulled Alberto's t-shirt over his head.

As soon as he was free, Alberto scurried into the surf and did a belly-flop, transforming in the spray of his own splash. He stood up laughing and stamping his flipperlike feet in the surf, and then turned to call for her.

"Ma! Ma!" he pointed out to sea, eager to make up for yesterday's lost time. "Ma!"

"All right, I'm coming," said Maria. She waded out into the water, feeling her own feet transform as the water washed over them. It made walking a little awkward – she had to lift her legs higher than she would have on land, or stub her toes on the seafloor. Something to remember. She took Alberto's hand, and let him lead her out into deeper water.

He was intent on where he was going, and didn't seem to notice the transformation creeping up her legs. Maria, however, could feel the slow-moving ripple, and it made her stomach tighten. This was it. She was going to go swimming with her son the way Giancarlo could... the way she'd always wished she could join in on.

Soon there was enough water for Alberto to duck under and propel himself with his tail instead of his feet. Maria let go of his hand so he could go, then breathed in and dropped into the water herself.

When she'd done this from the fishing boat, she hadn't thought about her vision – it hadn't been on her mind. Now she looked around, and suddenly realized that she could see. Underwater was usually a blur unless she was wearing a swimming mask. Now everything was crystal-clear. The stony bottom sloped steeply away into deeper water, with patches of multicoloured seaweed and objects like shells and old bottles of danced across it, refracted by the moving surface. And Alberto was swimming ahead of her, the light flashing silver off his scales.

"Alberto!" she called out. "Wait for Mamma!"

It was only after the words were out that Maria realized she hadn't known until that moment if she even could speak underwater. She'd never heard Giancarlo do so, but then, he might have held off just because he knew she couldn't reply. As a small child Maria had tried to talk underwater, and not only had it been unintelligible, she'd almost inhaled water and drowned herself. Now, like her eyes, it was clear as a bell.

Alberto definitely heard and understood it. He turned to face her, and his already large eyes went even wider. For a moment he floated there staring, and then he darted back to grab her hand and examine it.

"Yes, it's me," said Maria. She rubbed her thumb over his tiny fingers. "What do you think?"

Alberto reached up to tug on one of the fins around her face.

"Ouch!" she squeaked. It wasn't as painful as pulling hair, maybe because the attachment at the base was much bigger, but it did still hurt.

He let go and took her hand again, babbling as he tried to pull her after him further from shore.

"I'm coming, I'm coming," Maria promised. Swimming was, so far, slow and awkward, trying to use her tail the way Giancarlo and Alberto did, rather than giving in to the temptation to swim with her arms and legs. She was sure she'd get the hang of it, but it was going to take some practice. "What do you think? Can we find Uncle Massimo?"

Alberto burbled and let go of her to dive to the bottom, now about four metres away. He returned and presented her with a tiny, cherry-red object.

"Oh, isn't that pretty?" asked Maria with a smile. She took the item and found it to be a very small snail shell, no more than half a centimetre across. "Good find!"

Alberto beamed. He'd gotten over his surprise very quickly, and now seemed entirely unperturbed by her transformation. Maybe he assumed she could always do that, and just hadn't until now. He darted back into the weeds, and came back with another of the little shells. The previous one had been empty, but this still had a living animal in it, peering out with its stalked eyes.

"Very nice," said Maria. "What good eyes you have, to spot these little things! Let's put this one back so he can go home."

She placed the living snail back on the sand, and a moment later, Alberto was back with a piece of blue glass that had been tumbled by the sand so long that it had developed a cloudy, roughened texture, its sharp edges smoothed into harmlessness. Then he found a hundred-lire coin, followed by a smooth black stone. Maria laughed in delight. Alberto loved collecting such trinkets, and it always reminded her of the first time she'd seen Giancarlo on land. This stranger had come up to her and presented her with a handful of similar treasures. Maria had been utterly confused at first, so he'd dropped hints until she, astonished, realized this was the same being as the sea monster she'd encountered the previous day.

"Alberto, we're going this way," she said, turning to the right. Maria put his finds in her pocket and held out a hand. Her son came up and took it, and they headed back towards Portorosso.

The bottom dropped away to a couple of hundred feet, but then evened out. Maria didn't want to get too far from the surface, so she stayed high in the water where she had a wonderful view of the landscape below her. There were rock formations smoothed by centuries of current, interspersed with tall stands of waving seaweed in shades of green and purple, reminiscent of cypress trees swaying in the wind. Bright-coloured corals peeked out and silvery fishes flickered by, and there were vast swaths of seagrass with fish grazing on it or hunting small creatures living among the blades.

Alberto suddenly darted away and vanished into the waving grass. Maria stopped and looked around, trying to see where he'd gone. She heard giggles.

"Oh, are we playing a game?" she asked. "Where did you go?"

More laughter could be heard, and she saw motion in the seagrass. This was something Alberto had used to do back at the Island, finding places to hide underwater. Maria had sometimes gone half-mad looking for her, worried that he would go too far or too deep and she wouldn't be able to get to him when some danger threatened. He'd seemed to learn that Mamma couldn't do that, and stayed where she could find him. Now the boy had suddenly found that Mamma could go anywhere he did, and he wanted to play.

Maria went deeper and hovered above the waving seagrass, looking for motion. She saw a flash of silver, and reached down to grab her son. "I got you!"

It wasn't Alberto. Instead, what seemed like hundreds of little silver fish came out of the grass in a frenzy, followed by a small stingray that had been hunting them. They swirled around Maria in a whirlwind of glittering scales and then were gone, leaving her to listen to baby giggles echoing over the field.

"Little scamp! Where have you gone?" she called out.

A part of Maria wanted to find him quickly and get on with looking for Massimo – but it wasn't noon yet, and they had all day. Playing with Alberto underwater like this was exactly the sort of thing she'd dreamed of when Pinuccia had offered her the herb in the first place. She did have to find Massimo and take him home, but there was no reason not to enjoy herself a little. Alberto deserved it.

She followed the laughter and eventually discovered Alberto, hiding in between two rocks. He gave her a sharp-toothed grin when she found him, and swam out into her arms so she could tickle him and cover his little cheeks with kisses.

"Are you happier now?" she asked.

"Si!" said Alberto.

"That's good, but we need to find Uncle Massimo. We promised Auntie Helena we'd bring him home. We'll have lots more time to play, all right?" Hopefully the rest of their lives.

Alberto seemed all right with that. Being back in the water after skipping yesterday had put him in a good mood. Maria took his hand again, and they continued on their way.

Several more times, Alberto stopped to grab something and show her, or to wriggle into a little hiding place she would have to pull him out of. Maria didn't mind – he was having fun, and the underwater world was beautiful. The sunlight glittered on the surface, and lit up fish and sponges in all kinds of colours... and as they got further from shore, Maria began to notice signs of civilization.

The first were rocks and corals that had been arranged in lines, perhaps to denote boundaries. Then she spotted a set of stones that had been piled up and draped in seaweed, to make a sort of scarecrow in the middle of an open space. Nothing seemed to be growing there yet, but furrows had been dug – and as they passed over, Maria saw what was digging there. A green sea monster had two big groupers harnessed to a plough, and was leading them along while a couple of children, ten or twelve years old, guided the blade through the silt. One of the kids looked up and waved as Maria passed over. She waved back, then had to grab Alberto keep him from swimming down to join them.

"Not right now," she said. "They're busy. They're working. Maybe we can meet some people later." The Aragostas had told her there was a community in the area, but actually seeing it made it suddenly very real. Would it be all right to stop and talk to them? Maria didn't know anything about sea monster culture or etiquette. What if she did something horribly wrong?

Not only did the seabed below get busier, but so did the surface above. Further out, Maria began to spy the shadows of boats slanting through the water, and the long shapes of nets dragging behind them, visible only as a sort of shimmer in the sunlight. So far she'd stuck close to the surface, but now she went deeper, hugging the rocks that jutted up from the bottom around the island. What an iron it would be if one of the men seeking to avenge Massimo were to catch her.

The Island itself could be seen now, looming up with a forest of miniature mountains around it. Maria wasn't sure whether she ought to get any closer. Would Giancarlo still be there, now that she'd left, or had he gone elsewhere? Was that why he'd taken the boat, or was it simply because he felt it was his? Maria decided to give the place some berth.

Not far away, among the rough terrain ringing the Island, was a little saucer-shaped depression in the rocks that had filled with silt, making it a perfect sheltered spot for the seagrass to grow. A little school of fat, striped goatfish were grazing on it, and in the middle was a hunched figure sitting on a boulder, holding a hooked branch as if it were a shepherd's crook.

Alberto had seen several things he'd wanted to investigate, but this seemed to be the one he couldn't resist. He let go of Maria's hand, and darted down for a better look.

"Alberto!" Maria chased after him. "What did I tell you? People are working!"

The individual on the boulder straightened up, and revealed itself to be a young sea monster woman with a head of dark blue fins and something in a bundle on her back, swaddled in woven seaweed. She smiled and offered her crook to Alberto, who swam up and gripped it in both hands, then attempted to bite it.

"You can't eat that," the Shepherdess told him.

Maria hurried up to claim her son. "I'm sorry," she said. "We don't mean to bother you."

"It's not a bother," the Shepherdess assured her. "Honestly, it gets a little lonely out here sometimes. You're new in the area, aren't you?"

"Yes. Sort of. Yes," Maria decided. Alberto was staring at this woman the same way he did at new people in Portorosso, and Maria had to put some effort into not staring, herself, as the Shepherdess was the first sea monster she'd seen fully in the water other than Giancarlo or Alberto. She was plump and turquoise-blue, with a long snout and a fan-shaped fin at the end of her tail. The bundle on her back turned out to be a baby, younger than Alberto and fast asleep. Maria had a dozen questions she wished she could ask, about the fish, about the baby, and about the woven seaweed the Shepherdess was wearing as a tunic.

The only thing she actually felt safe asking, however, was: "have you seen my brother?"

"I don't know. What does he look like?" the Shepherdess wanted to know.

That was a bit of a difficult question. Maria had not seen Massimo transform, and Albino's description was probably not terribly accurate. Then she realized that of course, there was one feature she could always rely on. "You'd know him if you saw him. He's missing his right arm."

"I can't say I have, then," the Shepherdess said, "but I'll keep an eye out. I'll mention it to my husband and parents, too, so they'll know to look. You know who you ought to ask, though?" she added. "The Branzinos! Bianca and Ettore live out that way," she pointed with her crook, "at the edge of the ravine. Bianca likes to chat with the dolphins, and you know how dolphins always need to know everybody's business." She clicked her tongue disapprovingly.

"Yes, of course. Thank you," said Maria.

"Don't mention it," the Shepherdess said pleasantly. "Good luck. It was nice meeting you."

"You as well."

Her heart was pounding as she swam back up into the water column, trying to find a balance point where she'd be able to see some distance ahead but wouldn't be too close to the fishermen hunting above. That conversation had been awkward, but now that it was over, Maria felt rather proud of herself. She'd spoken to a sea monster in its natural habitat! Not only that, but she'd gotten some possibly useful advice. Massimo would probably hide from sea monsters if he saw them, but maybe one of them had seen him first.

Maria headed in the direction the Shepherdess had indicated, thinking as she did that she was in what were, technically, familiar waters now. She must have passed over this area in a boat a hundred times, and had never once wondered what was hidden beneath the surface. Massimo had similar experience with the area, and would be unlikely to try to leave it. He would have found a place to hole up. Maria just had to figure out where.

As she kept going, she started to see buildings. Maria hadn't really tried to picture what a sea monster community would look like, but she honestly hadn't expected them to build anything. What did you need a roof for, in a place where rain couldn't bother you because you were already as wet as you could get? Then again, there were probably predators around, and it would be nice to have a place to sleep without current constantly rushing by. As far as Maria could tell from a distance, the little houses appeared to be based on natural rock formations, with more stones piled up to turn them into structures. Many had seaweed or corals growing on top, suggesting they'd been there for a very long time. Around them were gardens, or farm equipment sitting around, or children playing.

It actually looked very much like the countryside above Portorosso, she thought. There were seaweeds here instead of vineyards, and Maria had no idea what these people were growing in their gardens instead of familiar vegetables and flowers – and yet there was something very ordinary about it, something very domestic. It was a community where everybody knew each other and they lived off the land and sea, just like the town where Maria had grown up.

Maybe that was why Giancarlo had never told her about this. He thought it would be too much like the thing she wanted to escape from. It would take all the romance out of a world under the sea. Yet now that she saw it, Maria found it had the opposite effect. Where Portorosso looked dull, this was just exotic enough to be temptingly idyllic.

Ahead, she could see a place where the bottom got suddenly darker. Was that the ravine the Shepherdess had mentioned? There were more buildings between her and it, including one that had fish gathered around it swimming at random, like sheep milling about waiting for their shepherd.

Maria paused here to think. The Shepherdess had said the Branzinos might have information from the dolphins and implied that they'd be willing to share it... but Maria was a foreigner here, and it was still possible that she would commit some kind of horrible faux pas without intending to. Her conversation with the Shepherdess, however, had gone fine. Could this really be that much worse?

Maria took a deep breath – sort of – and headed down.

"Hello!" she called out, as she approached the wandering fish. "Is anybody home?"

The man who appeared in response could not have been more of a shock.

"Who's out here?" he asked, sticking his head out of what appeared to be the fish' barn. Then he, too, stopped short. He was taller than Maria but not by much, dressed in an oversized plaid shirt and a pair of shorts that must have been pilfered from one of the boats, and was carrying a sack of something. His scales were deep blue, and he had gold eyes that matched his deep yellow fins. While Maria was staring at him, however, he was looking at Alberto, his eyes wide with recognition.

Alberto grinned. "Pa!"