Chapter Text
Wally's stomach twisted in discomfort as he was pulled through the Zeta tube, vision swimming and head spinning with it. The mer boy gagged, stomach roiling, as the world slipped back into focus. He blinked hurriedly to adjust to the low light he suddenly found himself in, from a room of brilliant shining chrome to a dark, dank cave. The humid air left Wally smacking his lips, the moisture only making him miss the water more acutely. He could smell that it was near, the tang of salt tickling an instinct he'd have assumed himself too human to possess. It made his scales itch to be out of the open air and back in the cool embrace of the water.
As Wally's eyes began to adjust to the darkness, the scene only became more and more difficult to process. The cave was humid and cool, with dark shapes which could only be bats clinging to the ceiling. Yet the floor was polished for walking, a massive computer and other assorted and strange technologies dominating Wally's view. Barry passed by it all without care, making his way to the far side of the cave where it began to narrow.
What Wally had first thought was a passageway revealed itself to be glass as they approached, glass holding back what had to several tons of water. The bottom of the tank that Wally could see was more glass, lined with those same smooth stones and gravel Wally had loved so much in the trailer. Though the tank had a shallow end where it would be possible for Wally to lay out of the water and crawl onto the cave floor, Barry did not approach that end, walking past to where the glass rose high enough his uncle was forced to climb a step stool to lower Wally into the water.
"We'll be right back, alright, little guppy?" Barry reassured as he pulled the water tank from around Wally's neck, "We're going to find Bruce and fill him in about your health. You just get comfortable in your new tank for now."
And then Barry dropped him, and the water rose up to meet him. Wally took a moment to right himself, suddenly in deeper water than he could ever remember being in. Upon being dropped, he immediately began to sink, flailing his fins for several seconds to bring himself back to the surface to meet his uncle again.
Maybe Arthur did have a point about Wally's swimming. That hadn't felt quite right, and Barry was now looking at him with worry creasing his brow.
"Is the water too deep?" Barry asked, reaching out to try and steady Wally against the lip of the tank.
The answer was yes, at least for now. But the idea of being in deep water was exciting, not scary, so Wally shook his head.
"I just gotta get used to it!" Wally chirped, "I can go to the shallow part if I get tired!"
Barry's expression didn't change, but he nodded nonetheless.
"Alright, Squirt," he relented, "We'll just be upstairs. Holler if you need anything."
Wally waved as Barry and Arthur retreated up the stairs, leaving the boy alone for the first time since leaving his father's basement.
Wally let himself sink back down into the water, savoring the way it engulfed his parched skin. The boy let his fins rest, sinking all the way down to touch the gravel at the bottom. Immediately, he realized it wasn't quite like what he had experienced in the trailer. Beneath the gravel was a layer of sand and dirt, which several long leafy plants clung to. Yet deeper into the water, the plants grew more thickly, and Wally found himself up and swimming once again to investigate.
The tank grew darker as Wally swam deeper, the glass bottom of the tank replaced with natural stone, sand, and algae. Yet the darkness bothered Wally little; he had spent most of his life in the dark, and was more than used to finding his way in low light. Here in the darkness of the caves, the water tasted saltier on his tongue, yet that too was not an unpleasant sensation. It felt natural, somehow, like a puzzle piece he didn't know he was missing was finally clicking into place.
A noise from deeper in the caves startled him at first, his fins fanning out in shock. He let the sound roll over him, a high pitched warbling he had never heard before. Yet, somehow, it felt so very familiar, conjuring up memories of a tiny bathroom and laying his small head against his mother's chest.
Staying close to the bottom, Wally swam off in the direction of the sound as fast as his short fins could take him.
The cave brached in many directions as he continued, but the sound continued to echo off the stone, helping him pinpoint which path he could take. Soon it became dark enough even Wally was beginning to have difficulty seeing, but the lights installed high above him out of the water still gave him enough light to make out the shapes of the rock around him. He had no clue how much water lay between him and the surface now, only that getting back up to the surface would likely be an exhausting swim.
Ripples in the water tickled the sensitive nerves of Wally's bobbles, leaving the boy fanning out his whiskers in hopes of capturing more detail. It was entirely instinct, something he had never needed to use his whiskers for, yet as the ripples grew stronger closer to the end of one bobble, he knew exactly which direction the disturbance was coming from.
He had no time to use this information, however, before the disturbance shot past him in the dark.
The warbling noise came again, this time from the dark figure now circling Wally. He had to be twice Wally's size, if not larger, long whip-like tail trailing behind him in the water. Wally had never been in danger before, had never encountered a predator. But all it took was a flash of a dorsal fin and long sharp teeth for his brain to catch up.
Shark!!
The wail that Wally let loose from his mouth was not voluntary, a high keening noise just as much from his gills as his throat. The predator stopped, and Wally bolted back the way he came, thrashing his tail harder than he ever had in his life. The creature warbled again, this time longer and lower, but Wally did not pause to see what the creature was doing. He shot back towards the mouth of the cave, tail thrashing and gills fluttering with the exertion. Arthur was right, he knew that for sure now, trying to swim quickly for long distances was painful, and his muscles were screaming out for him to stop. Yet he didn't dare, didn't even look back, just forced his aching body forward and back towards the light as the creature hurried on behind him.
He was slowing down. He knew he was. The cave walls moved by slower and slower as his body reached his breaking point. He didn't dare stop, pushing himself forward with his arms in his desperation, when he felt something latch into his tail.
Wally screamed again as the creature grabbed him around the middle, dragging him up up towards the surface. Wally hadn't realized just how far he had managed to swim until his head breached the surface and he found himself nearly back where he had started.
" Don't touch me!" Wally screamed, flailing frantically to get to the edge of the tank.
"Woah!" The creature said, though Wally didn't have time to process the fact it was speaking to him, " Wait! you're gonna-"
But Wally wasn't listening. The boy hauled himself over the lip of the tank, falling to the cave floor with a wet splat. The impact hurt, but Wally didn't hesitate, dragging himself away from the water on his elbows.
"You can't do that!" Called the voice, "Come back!"
" BARRY!" Wally screamed at the top of his lungs, " UNCLE BARRY! HELP ME!"
He could hear thumping from above him, as Wally's body became easier and easier to drag along the floor. Soon he went from dragging to crawling, to scrambling, not stopping until he was pressed against the far wall of the cave.
"Wally?!" Barry called out as he descended the stairs "Wally what happened?!"
The Flash looked about wildly for the little catfish he had let loose in the tank, only for his eyes to see the shivering, naked form of a human boy huddled against the cave wall.
Barry's jaw dropped. "Wally?!"
"He tried to eat me, Uncle Barry!" The boy wailed, his answer giving Barry all the information he needed. The speedster grabbed an abandoned black cape from the chair at the computer, wrapping it around his nephew.
"What?!" Came a voice from the tank, and finally Wally turned to look at his pursuer.
He was not wrong to say the creature was a shark. The sleek gray scales, tall dorsal fin, and many sharp teeth made that quite clear. But what the creature also was was a boy, mocha skin, black hair and blue eyes making that point clear as well. The shark mer leaned over the tank on his arms to get a better look at Wally.
"I wasn't trying to eat you!" The boy claimed, though the statement only made Barry hold Wally tighter.
"Then why did you grab me?!" Wally demanded, shivering against Barry's chest as the man stood up from the floor with Wally in his arms.
"You were struggling to swim!" The boy insisted, "I was trying to bring you to the surface!"
"That's enough, Dick," Barry snapped, and the shark mer fell silent with a pout. Barry ignored him, and focused instead on the boy held tight to his chest, "Wally, why didn't you tell us you could become human?!"
Wally hesitated, biting his lip, "It's never… worked before," He explained, "I could do it a little bit, I tried to practice so I could leave. But I only ever managed to grow toes."
"That's an astonishingly rare ability," came a voice from the stairwell, the pair turning to see Arthur and a dark haired man behind him.
"If he has a human form, does that mean he can stay with me and Iris?" Barry asked, and Wally could feel his arms wrap around him even tighter.
Arthur shook his head. "No, I've never known of a mer who could hold their human form more than a few hours at best."
"I can't just practice?" Wally piped up, looking at Arthur hopefully, "I wanna go with Barry!"
Arthur sighed, walking over to the pair and gently ruffling Wally's wet hair.
"I'm sorry, little one," Arthur said somberly, "Perhaps if you practice you can spend more time with him out of the water, but I don't think living on land full time would be a good idea."
"He's growing scales again," the dark haired newcomer pointed out. Wally squinted at him, before pulled the cape up around his waist to looks at his legs. Sure enough, as Barry and Wally looked down, Wally's skin was turning that same red-orange of his scales.
Barry and Wally noticeably deflated. Wally would have loved nothing more than to go with Barry, but it seemed the two men were right. At least for now, it wasn't in the cards.
"You should get him back in the water," the dark haired man continued.
Barry sighed, but did just that, Wally turning his suspicious gaze to the shark mer as they approached the tank.
"You won't let the shark hurt me, right Barry?" Wally whimpered into his chest.
By the time Barry ascended the stairs Wally was all but Mer again, but that did not stop Barry from kissing him on the forehead.
"Of course not, Guppy," Barry promised as he lowered him back into the water, "He's a very nice person, and a good friend of mine. But I should have considered the idea that seeing a predator mer would scare you. I'm sorry, Wally."
The shark swam closer, looking somehow smaller than he had deeper in the caves. Seeing him in the light, Wally could tell from his face he was younger than him. 11, at the oldest.
"I'm real sorry I scared you," the boy said, fins flapping anxiously against his sides, "I should have realized you wouldn't know Mer speak. I should have approached you above water, where you could understand me."
Wally furrowed his brow, leaning against the glass and his uncle but grateful to be back in the water.
"Oh… so that was the noises you made in the cave?"
"Yeah," the boy admitted bashfully, "I guess I got too excited. I haven't seen another Mer since my… well, in a really long time."
Wally smiled a little at the other boy, feeling rather embarrassed himself.
"I've never met another Mer," Wally admits bashfully, "Not since I was a baby, at least,"
Wally's smile seemed to soothe the younger mer, who offered Wally one in return. His sharp teeth were visible, but the smile was so charming it was hard to be afraid.
"My name's Richard! But my friends call me Dick!" The boy chirped with an excited little wiggle.
Wally couldn't help but giggle at the other boy's eagerness. "My name's Wally."
"Hi Wally!" Dick replied with a somehow even wider grin, "I'm so excited you're here! I've got all these caves and this big tank all to myself, so there's gonna be so much room for us to play in!"
Wally wasn't forced to dignify that with a response, as the dark haired man came forward, putting a gentle hand on Dick's shoulder.
"Let's not overwhelm our new friend too quickly, okay chum?" He said to the shark, who ducked his head bashfully.
"Oopsie," He squeaked out.
The man then turned to Wally, piercing blue-white eyes still gentle despite the somewhat stern face they were attached to.
"It's nice to meet you Wally," the man said, "My name is Bruce. I'm going to be taking care of you for the foreseeable future."
Wally pressed closer to Barry over the lip of the tank, the speedster wrapping his arm around the boy's shoulders to steady him.
"You're… my Uncle Barry's friend?" He asked tentatively, "You're… Batman?"
Bruce cocked an eyebrow at Barry, but took the question in stride.
"I am," he told Wally, "I wasn't aware you knew that, but given you'll be living in the Batcave, it wouldn't stay a secret for long, regardless."
Wally perked up, now leaning into Bruce's space rather than away from him. "This is the Batcave?! Really?!"
Batman gave an amused chuckle, something Wally would never expect from Batman.
"It is," Bruce agreed, "There's plenty here to keep you entertained. I let Dick watch movies on the batcomputer on weekends. He has plenty of toys I'm sure he's excited to show you, as well as other animals in the caves he likes to play with. Plus plenty of books and magazines to share."
"I have all the best comic books!" Dick chimed in with a proud puff of his chest.
Wally turned to the other boy with an excited wriggle. "You read comics too?!"
"Yeah!" Dick exclaimed, now circling Wally in his excitement, "I keep all my books and comics in my reading cove by the Batcomputer so they don't get wet! Do you wanna see?"
"Do I ever!" Wally declared, diving after Dick where he swam to the shallower end of the pool.
Barry turned to Bruce as the boys swam away.
"Be gentle with him?" He asked his friend, brows still drawn tight with worry, "He's been through a lot."
But Bruce wasn't looking at Barry. His gaze was captured across the cave, where the two mer boys had resurfaced in the little reading pool Bruce had built for Dick. Dick laid back on the lip of the pool, reaching up to peruse the collection of comics on his shelf. The once nervous koi fish had found a comfortable spot in the pool by his side, whiskers quivering in his excitement. Bruce smiled.
"I think little Wally is going to do just fine here."