Shiny things weren't Alberto's number-one favourite – he preferred finds that had moving parts, or parts that had used to move, so he could sit down and take them apart and try to figure out what they did. But shiny things were definitely fun to find, and he wasn't going to pass them up.

On this particular day, he'd already found several shiny things. He'd picked up a couple of pieces of cloudy sea glass, and a bent disc of the yellow metal that stayed bright no matter how long it was under the water. Alberto was putting them in the rusty bucket he used to carry stuff back to the surface when he noticed something else gleaming in the mud of the seabed. When he pulled it out, he found a little round object, a bit bigger and thicker than a sand dollar. One side was degraded by months of salt water, and had a couple of barnacles attached to it. The other was caked with silt, except for a bit at one edge where it caught the light like the surface of the sea on a sunny day. Intrigued, Alberto tried to clean some of the dirt off it, but it became a cloud in the water and the particles got stuck in his gills. Instead, he tossed it in the bucket with the rest of his collection, and head back up.

At the surface, he squatted in the surf and finished cleaning the object. When he tilted it, it gave off a flash of light so bright it was almost painful, as if the object contained a second sun. Alberto dropped it in surprise, and it fell upside-down on the sand.

After blinking the spots out of his eyes, Alberto scooped it up again and turned it over, more cautiously this time. Instead of another flash, in its surface he saw the blue sky with clouds. It was a mirror.

Dad had used to have one of those. He kept it propped on a crate and would look in it while trimming his moustache, or to check the angle of his hat when he was planning to go somewhere humans would be. Alberto had never been sure why Dad cared if he looked impressive for the humans, but he did know that a mirror showed you yourself. He could vaguely remember playing with one as a child, watching his reflection copy his every move.

Now he finished cleaning this one, then moved it around until it found the sun again, throwing a little circle of bright light onto the rocks and trees around the beach. With practice he could make this move almost wherever he wanted, like a butterfly flitting from flower to flower. When the novelty wore off that, he turned the mirror over and looked directly into it.

Alberto had an idea of what he looked like. He'd seen his reflection in the surface of the water from both above and below, and he remembered Dad telling him he'd gotten his green eyes from Mom. Now when he looked at his reflection, it suddenly struck him how much he looked like his father.

Like Dad, Alberto had a long face with ears that stuck out, and curly light brown hair. He'd never noticed how pronounced the resemblance was before. Maybe it just because he didn't remember Mom very much... he thought he recalled that she'd had dark hair, but he didn't remember at all what she'd looked like in the water. Maybe if he'd had a better idea what she had looked like, Alberto would have been able to see her in himself, too.

Or maybe not. Could that be why Dad left? Because Alberto looked too much like him and not enough like Mom? Or what if it was because he did have Mom's eyes, and seeing them made Dad sad?

Those thoughts made Alberto kind of want to toss the mirror back into the ocean, but he decided the thing where it reflected a spot of the sun was cool enough to keep. He put it back in his bucket and headed up the hill to the tower, where he could find places to store his new treasures.

He didn't exactly want to hide the mirror, but he did put it in a drawer and didn't think much more about it for weeks. Sometimes he did wonder if it could be used to start a fire the way a magnifying glass could, but he already had one of those anyway, and it could almost be used to examine weird bugs. Every time he thought of playing with the mirror like he had on the beach, he remembered looking into it and seeing a younger version of Dad, and decided against it.

A few months went by. Winter ended and spring came, bringing Alberto's birthday in June. He'd sort of hoped that if there were any day Dad might come back, it would be then. He'd always used to bring Alberto a treat on his birthday, chocolate or torrone or hard candy. When Dad didn't show, it was like going through it all over again... like sitting on the beach by a campfire staring out to sea, while it slowly sank in that this time, he really wasn't coming back. The last thing Alberto wanted at that moment was to be reminded that he looked like his father.

Then, a week into July, came the best thing that had happened to Alberto in a very long time. He made a friend.

He might have sort of kidnapped a friend, since he'd had to literally drag the kid onto the beach, but how was Alberto supposed to know that Luca had never been out of the water before? Besides, it was kind of funny watching him freak out. Luca rolled around in the pebbles and yelled for help like he thought he was dying or something, rather than going through a perfectly normal and natural process to adapt to dry land. Once Alberto reassured him and taught him how not to fall on his face, he was fine.

Alberto hadn't realized just how lonely he'd been until suddenly he wasn't anymore. Luca could probably have been the most boring kid in the world and Alberto wouldn't have cared as long as he was company, but Luca turned out to be amazing . It was his idea to build their own Vespa, and to turn the crank on the Magic Singing Lady Machine extra-fat so she would sound like a dolphin. In return, Alberto tried very hard to always have something new to show his friend. He didn't want Luca to get tired of him and do like Dad had done, just leaving one day and never coming back.

Four or five days after the two boys met, Alberto was digging through some of his old clothes, hoping to find a shirt that would fit Luca and prevent him from getting another sunburn. He eventually found one with almost all its buttons, and a pair of shorts that looked about the right size. When he looked out the window, however, he found that Luca had wandered off.

With his heart in his throat, Alberto scrambled down the ladder to look for him. To his relief, Luca hadn't gone far. It had rained the previous night, and a muddy little puddle had formed on the north side of the tower, where the morning sun hadn't had a chance to evaporate it yet. Luca was crouched next to that, staring into the shallow water.

"Uh... what are you doing?" Alberto asked.

Luca straightened up, embarrassed. "I was just wondering what I look like," he explained.

Of course, Alberto realized: Luca had said he was new at this. He had no idea what he looked like as a human. He might barely know what he looked like as a sea monster. Alberto remembered something he'd put aside months ago, and grinned.

"I've got just the thing," he said, grabbing Luca's hand to drag him back to the ladder. "Come on!"

Back in the tower, Alberto ransacked his things until he found the little round mirror and held it up triumphantly. "Here!" he said. "You can see yourself in this !"

Luca accepted it as if afraid it would explode, and took a deep breath before turning it over to examine his reflection. His eyes narrowed, then went wide. He reached up to squeeze his nose, then pulled on his earlobe, and finally tugged on one curl of his hair and let bounce back into place. A shiver ran over him, but then he smiled.

"Wow," he said. "It's so weird that's me ."

"You'll get used to it," Alberto told him, as he had about a dozen other things, like not having a tail or having to blink or your eyes would dry out.

Luca didn't answer. He was staring at his reflection again, stuck in his own head. To bring him out of it, Alberto looked over his shoulder into the mirror, and crossed his eyes and stuck out his tongue. Luca started laughing, and then made a funny face of his own. They entertained themselves like that for a few minutes, until they were both giggling helplessly and Luca had to wipe his eyes on the back of his wrist.

"You look ridiculous ," he said.

"We both do – humans all look ridiculous. Come on." Alberto gathered up the armful of clothes he'd found. "Try these out. They'll keep your back from getting all peely again. Then you can look in the mirror and see what you think."

"Right!" Luca took the shirt and held it up, trying to figure out which end went up, while Alberto propped the little mirror on a stone on top of his broken chest of drawers. Luca wouldn't see Dad when he looked at Alberto's face in the mirror. All he'd see was Alberto, and that made Alberto himself feel a lot better.