There was a whole other world beneath the water, a world that Harry and Severus, or any human, had never seen. Until now.  Harry had no trouble seeing, despite the murkiness of the water. That was no barrier to his merman eyes, which could peer through the darkest depths and see as clear as crystal even through the stormiest seas.  This world was a study in deep blues and greens and black.  Myriads of small fishes swam past him as he glided through the water as easily as he could fly on a broom.  His tail was incredibly powerful, able to propel him great distances with a single stroke and his webbed hands cut the water like a scythe.

Some instinct enabled him to swim swiftly and competently, using his tail in sharp up and down strokes like a dolphin, rather than side to side ones like a fish or shark.  Some kind of invisible sonar allowed him to judge distances and objects as well.  He knew that the bottom of the lake was at least thirty feet deep, and covered with fine sand and water plants and various rocks and other objects which had been tossed into the lake over the years by students. 

Water washed gently over his gills, which were at the sides of his neck, hidden by a frill.  He also had a small frill along his elbow and was a sort of pale greenish color. His scales along his tail and flukes were a deeper emerald green and gold color and they shimmered slightly as he swam. His hair was fine and silky, an inky black with greenish-blue highlights. His glasses had vanished when he transformed and he supposed he didn't need them, since his eyes in his new shape saw perfectly fine underwater.  He longed for a mirror to see if his appearance had changed any more, he had heard that merfolk were quite handsome, hence all the legends about beguiling mermaids and stranded sailors.  The only piece of "clothing" he wore was a webbed belt, where his wand was attached.  Other than that he was bare from the waist up.

Severus was swimming with long sure strokes a little ways ahead of him, straight towards the middle of the lake and then diving down even further.  Strands of duckweed and other plants obscured Harry's sight for brief moments as he swam through them.  He quickened his pace, drawing alongside his father.

"Dad? Where do you think he could have taken her? I don't see any place where he could hide."

Severus turned to look at his son, his gills fluttering on either side of his neck as he spoke. "We haven't even gone down halfway to the bottom of the lake yet. This is only the top half, where the freshwater kelp grow towards the sun." Tiny bubbles  accompanied his speech, which sounded odd, probably due to the way the water distorted sound. It made his father's voice deeper and more compelling than normal. He felt the rich timbre slide across his skin, it made him feel all quivery.  Harry wondered how his own voice sounded.

Harry rolled over, splashing with his flukes, delighting in the way the water felt, and how his sonar let him see that there was a large object some ten feet below him that he needed to avoid.  A very large object.  "Dad, what is that down there?" He backfinned sharply as a black tentacle covered with multiple suckers the size of Harry's hand came up from the depths.

"Ahhh!"

Severus grabbed his shoulder before he could panic utterly.  "Harry, it's just the giant squid.  Decius won't hurt you."

Harry stopped trying to swim away, feeling a bit foolish.  But the giant squid seemed so much bigger under the water than atop it.  His sonar sense told him exactly how big the squid was-about fifty feet, and thirty feet of that length was the arms.  He took a deep breath, trying to calm his racing heart.  It had never been proven that the squid was a carnivore, it always appreciated the crackers Harry had thrown it. 

"How do you know that? It's huge. Bigger than a bus, I think.  Maybe the size of the Hogwarts Express."

"Oh, I doubt he's that big." Severus chuckled.

Suddenly, the single tentacle that waved at them was joined by five or six more and then there was a tremendous wash of displaced water as the giant squid rose and looked curiously at the two unfamiliar merfolk who had paused in his domain. The giant squid's eye was the size of a tire, black and twinkling, sort of like Dumbledore in a good mood.  Its hooked beak was the size of a compact car.

Decius made a series of high-pitched clicks and whistles that Harry discovered translated to his mer ears as words.  "Greetings! I am called Decius. You are new here, I think.  Did you come through the Gate for the celebration at Prince Amphitron's palace?"

"What Gate?" Harry asked, before he could think better of it. It was positively odd having a conversation with the squid. 

"The one the prince's Wavemistress Celiafarrah opened to allow their sea-dwelling relatives access to the palace and its waters of course." The squid's eye blinked. "Are you perhaps unfamiliar with Gates, little sprat?  You seem rather young to be swimming with those of the Lake Court."

"And so he is," Severus interjected smoothly, before Harry could make the squid suspicious.

"You are his sire?"

"Yes.  And we are unfamiliar with the lake, as you have guessed.  We come from an isolated part of the Caribbean Sea and he has never seen a Gate before tonight."

"Ah.  As I thought. Welcome to the Black Lake . . .err . . .I didn't catch your name." The squid inclined several tentacles toward himself, which Severus supposed was a gesture of either welcome or respect.

"I am called John Hawkins and this is my son . . .Jim," Severus said quickly. He quietly thanked God he had read Treasure Island as a boy. 

"Well met, John and Jim Hawkins," Decius clicked his beak together.  "Were you exploring and got turned around? I can show you the way back to the palace."

"Actually, we're looking for someone," Harry interjected.  "A friend of ours . . .he's a kelpie.  We were wondering if you saw him and a pretty girl swim by recently."

"Hmmm . . ." Decius gave a long sigh that echoed through the water.  "As a matter of fact . . .I did see a kelpie go by."

"You did?" Harry was so excited he nearly swam circles about the squid.  "How did she . . .err . . .I mean he . . .look? How long ago was it?"

Decius trilled in amusement.  "He seemed fine to me and that was about twenty ticks ago. Not so very long, sprat."

Ticks? Harry thought in puzzlement.  He looked over at Severus.  Is that like minutes or something?

"Do you know where he went?" Severus asked.

"Down that way, towards the palace," Decius waved a tentacle down and to the right.  "Come, I shall show you."

He sucked in some water and squirted it out, propelling himself along rapidly.  "This ball of Amphitron's must be very spectacular. I have seen many strange merfolk tonight, giant sea horses, dolphins, and sea hags.  Sadly, no cephalopods majoris.  My people tend to stick to the great depths along the Great Divide, what the landlubbers call the Mariana Trench." Decius sighed.  "And we have gained a rather unfair reputation as carnivorous shipwreckers as well.  Honestly! I haven't capsized a boat since I was a little fingerling, only ten feet long.  And the only sailor I ever swallowed was during a hurricane out over the Atlantic.  I think the poor chap had drowned.  Matter of fact, that was how I came here . . .the hurricane warped the Gate terminus and I was shoved through it to here. Then it closed and I was stuck."

"But couldn't that Wavemistress send you back to where you came from?" Harry asked, feeling sorry for the squid now. Sorry and kind of disgusted.

"No, because she was too young at the time to weave a Gate.  And by the time she was grown and had mastered her magic, I had been living here for one hundred seasons and I no longer desired to return.  This is my home now.  I am content here as the Prince's guardian and the young wizard sprats feed me the most interesting things and some of them are even bold enough to swim with me. And I have fun chasing away the grindylows and kappas from the palace and the kelp forest."

They emerged from the waving green and yellow fronds into the deepest part of the lake.  Several dolphin lengths below upon a rocky shelf, was the palace of the Black Lake clan, formed of limestone and sponge coral and gilded with gold and pearls.  It glistened and rippled like a precious jewel.  Dozens of jewel like fish and glowing eels wove their way in and out of the coral gates and sculptures. Rays and crabs scuttled across the sandy bottom, slipping in and out of the rocks and among the blue and white sea ferns. 

To the left of the palace was a blue and white shimmering stretch of water.  "That's the Gate," Decius said, pointing with a tentacle.  "And there's the palace.  If your friend the kelpie is anywhere, he should be there."

"Thank you, Decius," Severus said formally.

"You are most welcome, John Hawkins.  May the waves send you good fortune. Fare you well!" And with that, the giant squid shot away in a cloud of ink.

Severus and Harry glanced down at the palace and then began to swim towards it, hoping that the kelpie had decided to hide near it and not in it, for fear of being noticed. 

"How much longer do you think we have?" asked Harry worriedly.

"I believe we have three hours left. Approximately." Severus answered.  "And I strongly suspect that the kelpie is not hiding among the merfolk of the palace.  That would be too obvious as well as conspicuous."

"Yeah, I figured that too.  What about the ferns and rocks around it?"

The two swam quickly into the fern forest and checked all the rocks that might have had sea caverns inside, but nothing turned up.  Harry felt himself growing fearful again.  How could they possibly find a creature who was at home in the water and who knew the lake back to front? "What if he's using magic to conceal himself, Dad? What if we already went past the spot he was hiding?"

"Harry, a kelpie is a shapeshifter, true, but he can only take the forms of a horse, a man, and a sea serpent.  I have been checking for Glamour and DisIllusionment Charms as we swam and I felt none." Severus explained. 

They swam about the backside of the palace, where they saw large structures with huge sea horses tethered beside them wearing sea grass woven halters. Dolphins lolled there as well, smiling their eternal smile, hitched to a gilded carriage carved from a pink conch shell.

"Hullo! Hullo!" they whistled cheerily when they caught sight of the two mermen.

Harry waved back at them, feeling his spirits brighten a bit.  He had always liked dolphins.  Then he turned back to Severus and said softly, "Why couldn't the blasted water horse be more like a dolphin, all happy and helpful, instead of some sour git that likes to play tricks on people?"

"Because that is its nature, Harry. Most fae creatures live centuries and they have always been temperamental and fond of playing tricks upon unsuspecting mortals. I think they do it more from boredom than true maliciousness.  Some can be rather cruel, but the same may be said of humans."

"Some game, playing about with a person's life!"

"Sometimes the fae are impulsive and capricious, rather like spoiled children.  I think this kelpie is no different, but unlike his Unseelie brethren he may have a code of honor.  And if so, we must use that to get Katie back from him."

"If we can find him.  Do you think he went through the Gate?"

"That is a possibility.  You did mention that he said his home was in the sea, right?"

"Yeah, he said the potion had called him from there, I think," Harry said. He wriggled a little, for there were large bubbles coming up from small cracks in the rocky bottom and they tickled his fins. The water was also warmer here than one would expect, because of the jets of warm air accompanying the bubbles.

Underwater vents? He thought, wishing now he had paid more attention to his science teacher in primary school. 

The two were hovering just outside the prettily carved coral fence, where crushed shells and pearl dust formed a small walkway leading to a small turquoise door.  Harry glanced at it just as it opened and three very attractive giggling mermaids spilled out of it. 

One had pale hair the color of sea foam and a halter top beaded with pearls and tourmaline, her scales were the deep purple of the inside of a scallop shell and matched her lovely violet eyes.  The others who were bobbing up and down like corks and laughing, were also gorgeous, one had hair the same shade as a sealskin and amber scales, she was wearing a gold and ruby halter and more rubies on her ears and neck, and the other was a red-haired, green-scaled beauty that reminded Harry of Disney's Ariel turned seductive voluptuous siren.  She was wearing aquamarines and turquoises and had a pretty sea flower in her hair.

Harry felt his heart beat faster as they swam over, their voices were like music and put the finest human singer to shame. 

"Ooh, my aching head!" giggled the redhead.

"Anemone, I told you not to drink the plum wine when you bobbed for pearls!" scolded the brown-haired one, laughing.

"But it was so good, Tyra!"

The pale-haired one rolled her eyes and then caught sight of Harry and Severus. "Oh! Look there, girls! There's something else that looks mighty fine." She swam over, unlatched the small gate and glided up to them, her violet eyes appraising. "Neptune's trident, but you are a handsome one, aren't you?"

Harry couldn't tell who she meant and so he blurted, "Me?"

The other two had followed their bolder mermaid leader and giggled.  "Aww, Lorelei, the little one's sweet on you!"

"Sorry, small fry, but I prefer my men a bit more . . .mature," Lorelei purred, smiling not unkindly at Harry before turning to Severus and swimming lazily about him.  "I haven't seen you before, and believe me I'd remember, since you're built like a tiger shark, and put all those other sunfish in there to shame."

Her hand reached out and gave a startled Severus a pat on tail, close to where the bottom would be on a human.  "Hello, my name is Lorelei, want to go for a swim in the moonlight?"

"I . . .I'm afraid I cannot . . ." Severus began awkwardly.

"Oh, why not?" she pouted prettily. "Why are you out here then, if you're not bored to tears being in there, with all those dried up codfish?"

"I am looking for a friend," Severus said stiffly, trying his best to ignore the way she curved about him, her tail fins barely stroking against him, her hands gliding gently over his shoulders, her hair stroking the side of his face.  Great Merlin, what does she think she's doing? Trying to seduce me?

"I think you've found one," she laughed, fluttering her superbly long lashes at him.

"No, I mean . . .I'm looking for a different friend, my lady.  A kelpie.  Have you seen one?" He swam slightly backwards, avoiding her hands.

"A kelpie? Not the sort you need to be hanging out with.  Don't be shy."

"I'm not." Severus sputtered. 

"'Cause if you are, I know a private grotto . . ."

"We just want to find the kelpie!" Harry interrupted.  "He's with a friend of mine, we're . . .playing a game . . .of hide and seek . . ."

"Really?" giggled Anemone.  "I like hide and seek. Can I play too?"

"Ahh . . .maybe later," Harry blushed, for she was devastatingly beautiful.

Lorelei pursed her lips.  "What if I told you that I saw this kelpie you're looking for, carrying a human girl upon his back, one of those little witches from that magic school?"

"You saw them? Where?" Severus demanded, reaching out to grab her by the shoulders.

"Now, now, handsome . . .I'll tell you . . .if you'll give me one teensy little thing." Her tail wrapped about his in a fraction of a second and her arms pulled him close, until he was gazing right into her bewitching violet eyes. 

"What?"

"A kiss. Kiss me."

"I . . .I . ."

"Or else I shan't tell you a thing."

She was mesmerizing, her voice was like silk and her hands caressed him in a way that he hadn't experienced since his last night with Sarai at Prince Manor.  Abruptly, the spell she was weaving popped like an exploding soap bubble. Sarai.  She'll have my guts for garters if she knew I willingly kissed a mermaid. Severus thought, flushing. 

"I mean it." Lorelei said, and her amethyst eyes grew hard.

"Dad, we're wasting time!" Harry cried in alarm.  The more time they spent with these beautiful yet fluffheaded mermaids, the further away the kelpie was getting.

Dammit, he's right. My student's life is at stake. Severus huffed.  It was just one kiss, it didn't mean anything. "Very well."

He leaned in and gave the pouting coral lips a brief peck.

"Now, tell me where the kelpie went."

Lorelei shook her head.  "You call that a kiss?" Before he could move, she had pulled his head down again and kissed him deeply and passionately.

Harry's eyes grew wide.  Holy Merlin!

It seemed to last for an eternity, but was actually much shorter. Lorelei drew away at last, her pale face flushed and glowing, her lips puckered in an adorable grin.  "Now that's a kiss.  Still want to go find that kelpie?"

Severus coughed, for he was not immune to her wiles, despite the fact that he was in love with his half-fae warrior.  "Yes.  Tell me, if you will, Lady Lorelei, where he has gone. It's . . .imperative that I speak with him."

The mermaid sniffed and pouted, swishing her tail.  "Oh . . .very well . . .he went across that way . . ." she waved a hand at the Gate.  "Towards the Coral Forest.  But there's nothing to do over there but look at boring old rocks and sponges.  You'd have a much better time with me."

"You are certain?"

"Yes."

Severus gently removed her arms and backfinned away. "Thank you for your help, my lady.  Now, my son and I must be going."

"So soon?" mourned Tyra.

"Come back quickly. We'll be waiting," Lorelei called, waving gracefully. "Ohh, how I wish I had a rope and I could tie him up in my bedroom! I hate letting a catch like that get away!"

"God save me from man-crazy mermaids," Severus muttered, feeling a faint blush crawl up his neck.

He swam rapidly towards the Gate, beckoning to Harry to follow.

"So what was it like, kissing him? Tell us!" the other two begged.

"It was better than anything you've ever known!" Lorelei gushed. "I felt like I was going to faint, like an air-breathing mortal maiden!"

Huge sighs of longing came from the other two mermaids. 

"Well, if he comes back this way, I want to kiss him next," declared Anemone.

"And I'll kiss his son, I don't mind tutoring the small fry in how to please a mermaid," chuckled Tyra.

Harry waved goodbye to the three mermaids, his ears flaming, if such were possible in this new form, and caught up to his father.  He took one look at his father's face, and began to giggle helplessly, rolling over and over in the water. A mermaid had kissed his father!  "Guess she really liked you, huh, Dad?"

Severus turned and glared at his son.  "I'm glad you find this so funny." Harry continued to laugh.  "Harry Albus Snape, if you breathe a word of what went on here tonight . . .I'll . . .I'll ground you for life."

Harry quit laughing.  "I won't, Dad. Promise.  Wouldn't want Sarai to kill you." Then he added, "But she sure was cute and Merlin, she had the hots for you."

"That's enough, Harry!"

"Okay, sorry." His son said contritely, turning away to stifle a giggle in his hand.

They swam through the shimmering Gate, leaving the warmth of the lake for the colder and wilder waters of the ocean. Ahead was the large forest of gold, red, and blue coral. 

"Dad, how can we ever find them in that?" Harry asked, despairing.

"I can cast a Locator Charm." Severus said.  "I think it should work, even here beneath the sea." He quickly drew his wand and cast the charm. Instantly, he felt an urging to go to the left, through the vast maze of coral.  "This way, Harry. Stay close, I don't want to have two missing teenagers to find before midnight."

Then the two stroked hard into the branched coral, following the tug of the locator charm, which drew them ever closer to the missing Katie and the sly kelpie who had stolen her away. Harry hoped desperately that she was not hurt and that the kelpie would keep his end of the bargain, for though the fae could not lie, they were masters at finding loopholes in bargains.