"~Albus, what is it you need?~" The Merchieftainess asked in her native tongue. It wasn't common for the Hogwarts Headmaster to ask to meet her, but whenever he did, he was always courteous and spoke Mermish.
"~I am sorry to request your presence so early in the morning, Merchieftainess, but I am in need of your assistance. It has been brought to my attention that one of my younger students has gone through some startling changes and now prefers to remain in the water. Until we can find a way to reverse the situation, would he be allowed to live in your domain?~" The old wizard requested politely, gesturing to where the Potter heir had drifted off to, a little ways away from where they both were.
Murcus was surprised by the request, and then even more so when she caught sight of a thin luminescent figure. The changed student held quite a few deep-sea salt water fish traits, but it was obvious they were human if only in the way the child smiled at her with bright, shining orbs.
The Merchieftainess offered a smile of her own before she waved to the child, who waved back in excited glee. They did not appear to be malicious or troublesome. The mermaid believed it would be quite easy to host this child.
Murcus turned back to Dumbledore as she asked, "~What caused such a transformation? The school year has not started yet, has it?~"
"~No~," the Headmaster confirmed. "~The school opens again in roughly a month. Harry here has apparently been living in the ocean for the past four years. I have yet to figure out just what caused this situation myself.~"
"~I see~," the mermaid replied, her decision already made. "~Do let me know what you find out. I would be most interested. However, does he understand Mermish? I would prefer to not have to swim to the surface every time he wished to speak if he were to remain with us.~"
Albus chuckled as he motioned for the child to come closer. Murcus watched the child with hidden mirth as he swam forward eagerly, the smile on his face shining brightly. In his excitement, the child seemed to be unconsciously giving off a glow similar to the anglerfish her tribe's Elder Selkie sometimes spoke of. Perhaps the child had seen such life if he truly had lived in the saltwater depths for so long.
It was as the old wizard pointed his wand at Harry that the Merchieftainess spotted the two small eels wrapped around his arms. Her clawed fingers twitched to grab them, and Murcus was reminded of why she was irritated to have been called by Albus so early. She had been on her morning hunt when she heard him call her name.
However, the eels appeared to be the child's pets, so the mermaid refrained from snatching them. She made a mental note to tell her people that they were off-limits. It would not do for one of her own to eat the friends of this child by accident. Pets were a respected object in her culture that none dared injure, and to hurt a child, physically or emotionally, was even more damnable. If only the wizards held their young in the same regards, Murcus thought angrily, thinking on the many children who had been hurt in the wizards' last war.
As a red light flashed and sunk into Harry's dark skin, the Merchieftainess was pulled out of her thoughts.
"~Can you understand me, my boy?~" Albus asked the child, and Murcus chuckled when he nodded erratically.
"~Hello little one, I am Merchieftainess Murcus, the leader of the selkie colony that lives within this lake. What is your name?~"
"~My name's Harry! But wait, if you're part of a selkie colony, does that mean you're not a mermaid, Miss Merchieftainess?~" The child asked, his bioluminescence dimming in a reflection of his emotions.
Murcus chuckled as she reached forwards to pat the adorable child on his head. The Merchieftainess noticed that he tensed slightly under her touch, but she dismissed that observation for now.
"~Well, you see, little one, I am a mermaid, as well as a selkie~," the mermaid replied. Seeing the child frown in confusion, Murcus continued, "~Just as humans can be a Scotsman or an Englishman, mermaids can be selkies, merrows, or siren. Does that make more sense, little one?~"
The child's mouth dropped opened lightly in surprise as he nodded, before his mouth opened wider in a yawn, his gills flapping open and shut to push the water he inhaled back out of his body. "~That's really cool, Miss Merchieftainess. I've always wanted to meet a real mermaid~," the child confessed, a tired smile lighting up his face.
Murcus shot a look at Albus before she swam closer to Harry and put an arm around his shoulders, starting to gently guide him towards the location of her home. Her morning hunt could wait a little while longer.
"~I am sure you have, little one~," the mermaid agreed, "~But it seems that the trip here must have been a long one, and you are tired. Let us get you to bed so that when you meet the rest of my people, you are awake enough to enjoy it.~"
"~That- sounds like a good idea, Miss~," the child yawned, relaxing farther into Murcus' grip as her warmth seeped into his body.
The rest of the swim to the mermaid's home went quickly, and Harry wouldn't remember any of it when he eventually woke up the next morning.