Milo flopped desperately on the bedcovers, struggling to draw air into lungs that suddenly didn't work right. Oh, no! I'm a fish! I have gills instead of regular lungs! I can't live outside the water!

"Get him into the water, quick!" yelled Uncle Fred, scooping Milo up into his hands and heading for the bathroom. Mia ran in front of him. Reaching the bathroom sink, she turned the water on full blast and filled the sink up as fast as she could.

Milo was straining for air. He was losing consciousness.but at last there was enough water in the sink. Uncle Fred practically threw Milo into the water, where he sank to the bottom like a small stone, too weak to swim. His brain was growing foggy, and he couldn't remember what to do. Uncle Fred and Mia huddled over the sink.

"C'mon, Milo, breathe!" panted Uncle Fred, and Mia added, "You can do it, Milo!"

Milo felt the cool water all around him, flowing over his scales and reviving him. He opened his mouth and gulped water in, feeling it flow through his gills. Life-saving oxygen entered his blood, and carbon dioxide flowed out of his gills into the water. Milo was breathing! Slowly he felt strength coming back into his body. He wiggled his fins and tail feebly.

Uncle Fred and Mia cheered. "All right, Milo! You're gonna make it! Come on, Milo!"

Milo's brain cleared and he could think again. He flipped his tail several times until he rose off the bottom of the sink. He moved his fins back and forth experimentally. Hey, these things work! I can swim!

His fins and tail moved him smoothly through the water. This is great! But where am I? All he could see was whiteness and water all around him. His fish eyes could see in practically all directions, though, so after a moment he spotted the two human faces looking down at him from above. He rose to the top of the water and tried to talk to them but all he could do was open and shut his mouth and gulp in more water. Not a single word came out. Oh, great. No way to communicate. And I had something I was going to tell them. What was it? I can't remember.still feeling dizzy.

Mia and Fred weren't concerned about his speech, however. "Way to go, Milo!" Fred said happily. "You're doing great!"

"He shouldn't stay in the sink too long," worried Mia. "He'd be better off in a wider fish tank, with a filter and more water surface."

So Milo was startled to find himself scooped up in something that looked like a large blue cylinder, and bounced roughly around in the water inside it. He figured out that the cylinder was probably one of his mom's blue kitchen glasses, but where were they taking him? A minute later he found out, when he was suddenly dumped into a vast lake of brilliant water.

Hey, what kind of fish am I? wondered Milo. He swam close to the side of the tank and checked his reflection. Yep, I'm a goldfish too. He looked around at the other fish, hoping they wouldn't be hostile. But unlike the other animals he'd been cooped up with, they didn't seem to mind an intruder in their tank. Maybe it was because he couldn't talk this time, so they didn't know he was any different. Milo swam all around the tank, enjoying the powerful swish of his tail. I wish I could have been this fast when I was on the school swim team.

Just then, the gleam of something shiny caught his eye. It was in the far corner of the fish tank. Milo darted over to explore. His blurry vision saw a fuzzy shape that looked like a tiny human! What the heck? he wondered. Swimming closer, he saw that it was actually a plastic decoration. One of those " cutesy" little things people like to buy and stick in their fish tanks, he thought. Now I know--it doesn't impress the fish. This one was a plastic "scuba diver" that emitted bubbles from its mask. At its feet was another decoration, a little plastic sea chest with fake plastic "gold coins" spilling out of it.

Milo tried talking again, but of course he just looked like a fish opening and closing his mouth, and no sound came out. He darted back and forth from the fake gold coins to the glass wall and Mia, hoping she'd figure it out. But Mia and Uncle Fred just kept smiling back at him. He could see their mouths moving, but he couldn't hear anything they said.

If he had been able to hear them, he wouldn't have been impressed. "Oh, look," cried Mia. "How cute! He's swimming around really fast! I guess he must be really happy in there."

"Hmmm." said Uncle Fred. "Maybe. Or maybe he just needs exercise. Anyway, I guess he's all right now, so we'd better leave him and open the store."

"Uncle Fred," said Mia later that morning, "What do you think Milo was about to tell us this morning? Before he turned into a fish, I mean?"

"I don't know," said Uncle Fred. "Something about the riddle, I guess. We'll have to wait until tomorrow to find out. He certainly can't tell us now."

Mia thought that Uncle Fred acted strangely all that day. He didn't seem as interested in solving the riddle or finding the strange old man any more. Instead, he kept asking Mia questions about her mom all day. He wanted to know how hard she worked to keep the store going, and how many hours she worked every week, and if she seemed tired a lot. He wanted to know about her mom's second job, too. Her mom sometimes worked in the evenings, going to parties and selling a line of kitchen products called Sipperware. It was a Sipperware convention she was attending now, in a faraway city.

"We can't let her know anything about what's happened to Milo," said Uncle Fred for about the thirtieth time that afternoon. "She'd be so frantic and worried. I don't want her upset."

What about me? thought Mia. I've been upset and frantic and worried about my brother, too. But you don't seem to be worried about whether I can handle it.

Just then, the phone rang. "Peterson's Last Stop Pet Shop," she said in her most professional voice. "This is Mia Peterson, may I help you?" And then she forgot all about being professional.

"Milo?" Mia gave a panicked glance at her uncle. What could she say? "Uh, he's all right. You know, he just sometimes-uh-acts like an animal. But I've been taking care of him."

"I guess all boys act like animals sometimes, don't they?" laughed her mother heartily. "But I'm sure he'll grow out of it soon. He's growing and changing all the time."

"Uh, you're right, Mom," agreed Mia. "You'd be surprised how many times he's changed in just one week." She rolled her eyes at Uncle Fred, begging for help, and he took the phone. Mia listened to his part of the conversation.

"Mary?" he said. "How are you doing? How is the convention? Good. Well, don't overdo it, dear. Be sure to do some sightseeing and have a good time. You deserve it, honey. I never realized how much work this shop-and raising these kids-must be for you. Oh, no, nothing's wrong-(he crossed his fingers)--everything is fine here. Running the pet shop has been much more-um-interesting-than I thought it would be. What? You want to talk to Milo?" He turned pale and glanced at the fish tank. "I'm sorry, dear, he can't talk at the moment. He's-uh-swimming." Uncle Fred gulped, looked at all the goldfish, and added hastily, "With a bunch of friends."

Mia choked. Uncle Fred glared at her and went on, "But he's fine. You just go ahead and have fun, honey. When are you due back home? In four days? Four days! Uh, oh. I mean, oh, how we're looking forward to seeing you when you get home, dear. Bye, now." He hung up and turned to Mia in dismay. "Four days-only four days to solve the riddle and get Milo back to his human self before your mother gets home. I couldn't stand it if she gets home and he's not back to normal. She'd be frantic! And she doesn't need that."

Mia was staring at Uncle Fred. What's with him? she thought. He's acting like my mother's feelings are the only problem. And I've never heard him call her "honey" and "dear" so many times in one conversation...I think this whole experience is making him a little crazy.

After dinner that night, Mia went down to the fish tank to tell her brother good night. "Good night, Milo," she said, peering in at all the goldfish and trying to figure out which one was her brother. "Milo?" she tapped the side of the tank, trying to get one of them to respond. "Uncle Fred?" she called upstairs to her uncle. "Do you know which of these fish is Milo?"

"Nope," he called back. "They all look alike to me."

"Then we have a problem," said Mia. "How will we know which one to take out of the tank when it's time?"

"I guess we'll have to wait until he changes," said Uncle Fred, coming downstairs. "Then it will be obvious."

"Yeah, but there's only one thing," said Mia. "According to my calculations, Milo should be a cat next. What if he eats all the fish before we get him out of there?"

He wouldn't do that, would he?" asked Uncle Fred, looking worried