Sweden carefully walked to the lab's whiteboard, while Finland guided him. "Let's start with Denmark!" Sweden proposed. The room filled with anticipatory silence.

Denmark grinned, crossing his arms over his muscular chest. "Bring it on!" He proudly declared, his voice echoing through the lab.

Sweden thought for a moment, then scribbled something on the whiteboard. "Thunder," he announced, "because he's as loud as a thunderstorm."

Denmark laughed, flexing his biceps. "Thunder, I like it!" He chuckled, his laughter echoing through the lab.

"Now it's Norway's turn," Sweden said as Finland helped him turn towards Norway, who was sipping his coffee.

"Seer," Sweden announced, "because he can see things that we cannot." Norway nodded, a small smile forming on his face.

Sweden then turned to Iceland, who was watching the proceedings with a bemused smile. "Your code name will be Blaze," he stated.

"Blaze?" Iceland asked, his eyebrows furrowing in confusion. "Why Blaze?" Sweden simply smiled, tapping his fingers on the whiteboard.

"Because you're cool on the outside, but we all know you're passionate, like a blaze," Sweden explained. Iceland blushed, but nodded in agreement.

Lastly, it was Finland's turn. Sweden's fingers gently traced the Braille on the whiteboard. "Guide," he announced.

"Because you're always there to guide me," Sweden said softly. Finland blushed, but he smiled warmly at Sweden. The lab was filled with laughter and joy.

The next day, Denmark stumbled into the lab, reeking of alcohol. He was obviously very drunk, and the others watched in amusement as he tripped over his own feet.

"Thunder is hammered!" Sweden exclaimed, trying to suppress his laughter. Denmark just grinned, waving his bottle in the air.

"Seer, help me!" Denmark wailed, clinging onto Norway. Norway sighed, using his magic to sober Denmark up.

"You owe me one, Thunder," Norway said, shaking his head. Denmark just grinned, patting Norway on the back. "Thanks, Seer," he said, chuckling.

Later, Iceland came running into the lab, his eyes sparkling with excitement. "Blaze, what's wrong?" Sweden asked, turning towards him.

"I've discovered a new species of sea creature!" Iceland exclaimed. The others were immediately intrigued, gathering around to hear more.

As Iceland presented his findings, Sweden listened carefully, a proud smile on his face. "Well done, Blaze," he said, clapping Iceland on the back.

The next few days were filled with excitement as they studied the new species. They worked tirelessly, their code names becoming a source of camaraderie and fun.

One day, Sweden slipped and fell. "Guide!" he called out, and Finland rushed to his side, helping him up. The others watched, their respect for Finland growing.

The code names had become more than just a game. They symbolized their strengths, their bonds, and their shared journey as marine biologists.

One day, Norway saw something strange in the water. "Seer, what is it?" Denmark asked, peering over Norway's shoulder.

"I think it's a troll," Norway said, his eyes wide. The others gasped, crowding around to get a better look. This was a moment they'd remember forever.

"Well, Seer, you've certainly made this an interesting day," Denmark said, clapping Norway on the back. Norway just smiled, his eyes still on the water.

They continued their work, their bond strengthened by their shared experiences. The code names had become an integral part of their journey, a testament to their friendship.