One night, Dory swam out of her cave. Through the gentle swaying fronds of the sea anemone she could see Marlin and Nemo sleeping.

Dory and Marlin went on an incredible journey across the ocean to find his son, Nemo. A year passed, and after their grand adventure, Dory decided to stay with Marlin and Nemo -- and join the community of the beautiful Great Barrier Reef. Dory had a cozy coral cave where she slept each night, and Marlin and Nemo lived in a comfy anemone only a few strokes away. Dory was able to remember more when they were together -- in fact, everything seemed better now that they had each other. She, Marlin, and Nemo were very close, and they always tried to keep each other happy and safe.

"Hey, Marlin," she whispered. She swam toward them and accidentally hit the anemone. It jolted her with an shock! "Ow-ow-ow-ow!" she cried.

Marlin awoke groggily and gently pushed her back into her cave. "Oh, Dory, it's not time to get up yet. You have to go back to bed."

"And remember, the anemone stings," Nemo said, still half asleep.

"I remember it like it was yesterday. Although I don't really remember yesterday all that well," Dory admitted.

"And we're up," said Marlin, realizing that he wouldn't be able to get back to sleep. "That's it. Ready to start the day."

Nemo giggled.

Now Marlin jumped up. "Go back to bed -- that's it. Very simple. Bed. Back to it," he said curtly, pointing a fin toward her home.

"Hmm. Found him!" said Dory happily.

"Oh, right. Yeah. Sorry. Back to bed, back to bed," Dory said, settling back down. But she quickly headed out again, hitting the anemone's stinging cells again. "Ow!"

"And we were looking for something," said Dory.

"Nemo," said Marlin.

Dory, Marlin, and Nemo followed the winding path that led to Nemo's school. As they often did, they reminisced about their great adventure across the ocean to find Nemo.

"Okay," said Marlin. "So, there we were, stuck inside a whale, hanging from his tongue --"

"Ah. Um… hmm. Got it," said Dory, once again swimming back to her cave. But then she turned around. "Hey, Marlin --"

"But last time you told it, there were three."

"That must have been the scariest part of the whole trip. Right, Dad?" Nemo asked.

"No, the scariest part of the whole trip were the four sharks."

"Nemo did," Dory said quickly. "Obviously, we had to cross the ocean to find him, so, you know… he went first."

Nemo looked at his father. "Wait, I thought there were three sharks."

"A field trip? Ooh, I love field trips. Where are we going?" Dory asked excitedly. Mr. Ray gave Marlin a look. "I thought you told her," he whispered to Marlin.

"No," said Marlin. "No, there were definitely four."

"Son, which one of us traveled across the entire ocean?"

Marlin stared at Dory, realizing she was right. Nemo grinned proudly at his father. "I guess that's true, isn't it?" said Marlin, smiling.

When they got to Sandy Patch School, the teacher, Mr. Ray, was pacing nervously. As Marlin, Dory, and Nemo rounded the corner, Mr. Ray swam toward them. "Weeeeell, you made it! You almost missed the field trip," the stingray said.

"He's… he's a teacher, not a scout!" Marlin said, laughing nervously.

"So he doesn't have enough help. To keep an eye on… on… on those who are not --"

"Well… you know how you have problems remembering things sometimes?" Marlin asked.

"Okay, and sometimes -- and it's not your fault -- but it can cause you to wander," said Marlin.

"Mmm-hmm."

"Okay."

"Sure."

"I did tell her," said Marlin. Then he turned to Dory. It was clear that he was going to have to explain the situation… again. "Uh, Dory…" he said, trying to get her attention. Dory listened with a smile on her face. "Mr. Ray has too many fish to keep an eye on today." Mr. Ray swam off toward the class as Marlin continued. "So it would be best if -- today -- you weren't, exactly…" Marlin's voice trailed off as he tried to figure out how to say what he needed to say without hurting Dory's feelings. "… with the class."

"Oh. Why not?" asked Dory.

"That's the one thing I can remember, yes," Dory said with a chuckle.

"Poor guy. You know, he is so overworked," said Dory.

"-- part of the group."

"Okay?"

"Ooohhkey-dokey," said Mr. Ray.

"Now, does anyone know why we migrate?" asked Mr. Ray.

"He wants me to be the teacher's assistant," Dory said proudly.

Marlin couldn't believe it! How could Dory get it so wrong? "Uh… no, not exactly --"

"Today's the day!" repeated Dory.

"Good," Marlin said, satisfied.

"All right, kids!" said Mr. Ray.

"All right, kids!" said Dory.

Marlin sighed, giving up. "Mr. Ray!" he called. "You've got help. Good luck!" Exasperated, Marlin swam back toward home.

No one responded. Mr. Ray was met with blank stares and a deafening silence.

"Our field trip to the stingray migration!"

"Today's the day!" said Mr. Ray.

"Well, I am so honored. I have never been a teaching assistant before," said Dory happily.

"Stingray migration!"

"I totally understand now," she replied.

Once the class settled, Mr. Ray began his lesson. Dory tried to help in her own way… by repeating everything he said.

Marlin wasn't sure that Dory was getting the full picture. "You understand?" Marlin asked.

"Um-hmm," said Dory.

"Yes!" said Dory.

"Where'd you grow up, Dory?" asked a young crab.

"Come on," said Dory, smacking her fins together. "You gotta know this stuff."

"No!" echoed Dory.

"No," said Mr. Ray.

"The sand!" answered Pearl, raising a fin.

"My house is covered in algae!" yelled Chickenfish.

"Migration is about going back to…," Mr. Ray offered, trying to give the class a hint.

"I live by a giant rock!" yelled one student.

"Can someone tell me where you're from?" asked Mr. Ray.

"Home," Dory repeated slowly. The word seemed to tug on something deep inside her.

"Bed!" said Chickenfish.

"Which is where you're from," said Mr. Ray.

"Where you're from…," said Dory thoughtfully.

"Me?" Dory asked, pointing her fin at her chest. "Um, I don't know…," she said, her big eyes shifting downward. The kids immediately quieted; they were surprised by Dory's answer. "My family?" she continued. "Uh, where are they?" Dory turned and stared out at the open water, lost in thought. Something in that conversation had jogged her foggy memory. But she could never hold on to those thoughts for very long. When the water ceased to hold her attention, she turned to see Nemo's entire class staring at her.

"No," repeated Mr. Ray. "Migration is about going home."

The class chimed in together, "Short-term memory loss."

"Can I help you?" she asked. They giggled. "I'm sorry." Dory was embarrassed. "Did I forget again? You see, I suffer from --"

"What's it like having short-term memory loss?" asked Chickenfish.

The class stared at Dory, bewildered, as she continued. She was forgetting right before their very eyes. "You say something about kelp and I'm like, what about kelp? But you're saying, 'You brought it up.' I'm like… okay, that's gone now, too. I don't even know what we were just saying. See, that's my problem… in a nutshell."

Dory smiled. "I try not to dwell on it," she said genuinely.

Mr. Ray jumped in, eager to move on. "Okay, kids, enough discussion. Climb aboard, explorers! I feel a migration song coming on!" He held a note as he sang, "Ooooooooooohhhhhhhhhhhhhhhhhhh --"

"Aw, that's so sad," said one young fish.

"Good question," Dory answered. She thought for a moment, then tried to explain. "Well, like, for instance, if I'm thinking about… say, kelp, and then all of a sudden -- What? And even though I just had the kelp in my head… I… See, I… I don't even know what I said just now, to tell you the example. Let's just say it's kelp."

"When the rays pass through here -- what do we have to be careful of?" asked Mr. Ray.

The class settled down and waited expectantly. "Now I need everyone to listen to me," started Mr. Ray.

He continued to sing a migration song as he carried the class on his back. Dory sang along, swimming next to Mr. Ray. When they reached the edge of the reef, the students jumped off and he reminded them to stay away from the edge.

"All right, listen up!" said Dory, continuing to repeat Mr. Ray's words.

"The undertow!" the students answered.

"Everybody has to be careful of what? Hmm?" echoed Dory.

"That's right, the under --" Dory said, stopping suddenly. "The undertow?" she said to herself. "I've heard that before." Dory was so focused on the word that even as Mr. Ray continued, his voice began to fade. Soon she didn't hear him at all.

"That's what instinct is, Nemo," answered Mr. Ray. "Something deep inside you that feels so familiar that you have to listen to it -- like a song you've always known." Mr. Ray perked up and held a fin to his ear. "And I can hear mine now!"

"That's right!" said Mr. Ray.

"Mr. Ray!" squealed Nemo, raising his fin. "So how do the stingrays all know where to go?" he asked.

FLASH! Suddenly a lightning fast clip of a memory played through her mind. She remembered being pulled away from her parents as they called her name. She heard their voices clearly shouting again and again. Then everything went black.

The sea grass bent, pulled by the strength of the massive current created by the flapping of the rays' fins. But Dory just stared at the swaying grass. The way it moved reminded her of something. She slowly approached it, as if in a trance. Then inside her mind, she heard a pair of faraway, frightened voices saying "Watch out, kelpcake!" and "You have to stay away from the undertow!"

In the distance, they heard the sound of a many voices, singing as one. It was like a choir singing a beautiful song. As the stingrays swam closer, the choir became louder and louder. Everyone watched, amazed. The massive school of rays gracefully swam and sang in perfect harmony. It was an awesome sight!

"The undertow," Dory said again, repeating that strangely familiar word. She drifted closer and closer to the rays and, all of a sudden, she was pulled into the undertow! She screamed as her body twirled and twisted -- the whirling water was completely overtaking her!

"DORY!" shouted Nemo. She continued to scream as she moved farther and farther away from Nemo and the rest of the class.