In the ocean, the Kratt bros and the team dove into the ocean with the sea vehicles' help.
"Are we in the right direction, Mina?" Chris asked his little sister, while piloting the Octopod.
"According to the map Mommy gave me, we're close," she answered.
Bite-Size just observed the sea through the Octopod's window. "Wow, I never thought there were so much stuff in the water."
"There are millions of species here, Bites. You spent your whole life on the surface. There was no way you could know this."
"There!" Mina pointed out to a coral door in front of them. Once they passed through it, they were amazed: there was a wonderful temple, full of pearls and coral.
"Here we are. Poseidon's temple," Luna announced. She and Mina left the Octopod without diving gear.
"Hey! You guys are gonna drown," Aviva warned.
"No, we won't, silly. There's oxygen here." Luna said, waving to them with her wing. With that advice, the Wild Kratts left their vehicles. Jimmy was covering his mouth and nose with his hands, until Koki gave him a soft slap on his neck.
"Why have you done... Oh..." Jimmy realized he could breath, while Koki and Bite-Size hid their chuckling.
"Welcome, Guardians, to my humble temple," Poseidon itself received the Wild Kratts. Mina ran to embrace him. "And hello, my little niece. I haven't seen you since your sister died."
"Well, let's just say plenty of stuff happened, Uncle Poseidon," Mina said.
Suddenly, Martin's medallion started floating by itself and dragging him. "Hey! What's going on?"
The Sea God immediately clapped his hands, calling for help. Three swordfish and a younger one helped Martin slowing down.
"Are you okay?" the younger asked.
"Yeah... I think so..." Martin said. Seeing his medallion was still pointing to somewhere, Martin followed the medallion's direction, and touched a certain wall of the temple, opening a secret compartment... with a sword on it. "Wow..." The sword had a sky blue grip and guard with a blue stone as its pommel. There was even another stone in the middle of the guard. The main part of the sword was long and silver.
"You must be one of the Guardians," One of the swordfishes said. "That sword belonged to the previous Water Guardian. For right, it now belongs to you."
Martin smiled with that and picked up the sword. "It's beautiful," he said. Then, his medallion started glowing again and the sword converted into a blue light, entering it.
"Well, looks like Chris is no longer the only one with a weapon," Martin said, with a smile.
"Also, according to the Musketeer Law, you must stay here in the temple... forever," another swordfish said.
"Well, that's interesting, I never actually had a... whaaaaaaat?" Martin asked, shocked.
"Forever?!" the others exclaimed, equally shocked.
"Letter to the Wild Kratts!" A seahorse came into the temple quickly. "From Mother Nature."
"Lemme see." Bite-Size grabbed the letter. "Dear Guardians, I fear you will have trouble. It was heard from some of my "agents" that one of your enemies is looking for swordfish to cook!"
"GOURMAND!" They recognized the description.
It was Gourmand. He approached the place with his boat, looking for his ingredients.
"Swordfish stew. Why haven't I thought about that before? They may not be endangered, but who has ever tasted something like this?" he spoke to himself, as he prepared to dive.
Later, in the temple's garden, Martin was worried. Leaving his friends? Not living other Creature Adventures? Staying forever? He sighed sadly. Then, his thoughts were interrupted by a voice.
"So... wanna practice?" It was the younger swordfish.
"Sure." Martin said, activating his new sword.
After some battles, Martin was defeated. "Touché," the swordfish said.
"Wow, you're good."
"Thanks. I always train, cause I'm dying to go on patrol with my brothers, but they don't let me because I'm too young. I have been practicing since I was saved by them from a fishing net," the swordfish said.
"Hmmm...this reminds me of a book I read once." Martin picked up a book on his backpack. "The Three Musketeers. It's about a young man named D'Artagnan, who joins the royal musketeers Athos, Porthos and Aramis to save the kingdom."
"I guess Poseidon also read this book. Athos, Porthos and Aramis are my brothers' names," the swordfish exclaimed.
"So it would be fair if your name was D'Artagnan," Martin suggested.
"Yeah, I like this name," D'Artagnan said. "Suddenly, I feel way more included on the team."
Later, the fish-keteers talked among themselves, trying to find a way of protecting the temple against the thief.
"We could put more guards at the entrance!"
"No way, they need to protect other rooms! What if the thief finds another way of entering?"
While they were discussing among themselves, Gourmand really found another way to get into the temple.
"Atlantis may be a myth, but this temple is not! And it's full of delicious swordfish to cook!" Gourmand thought, not noticing the dark magic cloud escaping his hat and hiding in the shadows. "I'll wait until they get distracted, and then, there'll be swordfish stew in my menu!" Gourmand cackled evilly.
That night, the Wild Kratts were all asleep on their rooms, except for Martin. Leaving his room to take a look around the temple, the Kratt in blue couldn't stop thinking about leaving his brother and family. That was so unfair...
Suddenly, he saw D'Artagnan mumbling on the garden.
"Hey. What's up, D'Artagnan?" Martin asked.
"My brothers didn't let me join them in patrol again... and you?"
"I'm still bugged about this whole thing of staying here forever. It's so unfair!"
"Well, it is Poseidon's law. He believed that his fish-keteers should remain here to protect the temple in all occasions."
"But don't they miss their families? Their home?" The Kratt in blue did have a point.
"Maybe..."
"I think we should speak with Poseidon about this law. It is clearly unfair," Martin decided, and D'Artagnan agreed.
Suddenly, they heard a scream from the hallway, and ran to see who was it. It was Aramis, one of
D'Artagnan's brothers. The Wild Kratts also heard the scream and ran to see what was going on.
"What happened, Aramis?" D'Artagnan asked.
"It's horrible! Our brothers were taken by a human in white to the surface! He said they would be perfect for his soup!" Aramis said, desperately, making the others gasp.
"HELP!" The seahorse who brought Mother Nature's letter previously appeared. "Poseidon's trident was taken away by some kind of dark cloud!"
"Dark cloud?" Luna asked. "So these troublemakers are back..."
Once Poseidon was woken up, the Wild Kratts told him about the incident.
"We need to get them all back. The trident and the fish-keteers," the Sea god stated.
"Leave Gourd-mand to us," Mina said. The Wild Kratts agreed.
"Then let's go!" Martin said.
"But what about the Musketeer Law?" D'Artagnan reminded him.
"Listen, I may be a new musketeer, but I'm still a Guardian!" Martin said. "My siblings and friends need me, and I'm not letting an unfair law like that stop me from doing my duty."
Poseidon, hearing these words, thought about the Musketeer Law.
Maybe the Water Guardian was right. That law was unfair... because by keeping the fish-keteers in the temple, he has been keeping them from seeing their families and helping other sea creatures.
"I'm going after the dark cloud, you guys search Gourmand," Martin said, with the posture of a leader.
With all agreed, the Wild Kratts left Poseidon's temple.
"Come out, you dark monster!" Martin challenged, once he got on the surface. "I know you're here!"
The dark cloud appeared, with the trident within it.
"You may not have a physical form, but I'll defeat you!" Martin summoned his sword. "En garde!"
What Martin didn't know is that the mysterious statue was observing everything. "You want physical form, huh? Here you go!" her distorted female voice was heard, and its eles glowed.
The cloud assumed the form of a warrior with a dark sword. "Bring it on," he challenged.
*BG music: Agent Orange - Bloodstains*
The duel was pretty balanced for a while, until the cloudman knocked Martin down. Then, the Kratt in blue remembered how he defeated the last dark cloud he faced.
Closing his eyes, he thought about everything and everyone he loved and wanted to protect. Soon, his bravery was manifested into his sword, making it a double edged Medieval sword, and in one single attack, he defeated the cloudman, making it run away and leave behind Poseidon's trident.
"Now, after Gourmand," Martin said, proudly.
Martin reached Gourmand's boat quickly, seeing the team trapped by doughballs.
"Let them all go, Gourmand!" he challenged. "Or you'll not like what I'll do."
"Oh, I'm so afraid of Blue Berry and his little stick!" Gourmand mocked.
"Oh, yeah?" Martin concentrated his bravery on the sword again and sliced the net, freeing the swordfishes, who quickly jumped in the water. Then, he sliced the doughballs, freeing the team and turned to Gourmand. "Not bad for a stick, huh?"
Gourmand gulped. Martin hit the boat, opening a hole on it and making it slowly drown. Gourmand caught his jetpack and escaped.
"You haven't seen the last of me! I'll be back!"
The Wild Kratts hopped to their sub-vehicles, and dove back to the temple.
"I don't know how to thank you all enough for the help," Poseidon said. "This trident has powers beyond comprehension."
Martin sighed. "I guess this is good-bye, guys," he said, not forgetting about the Musketeer Law. "Will you be okay?"
"Sure they will. After all, you'll be going with them," Poseidon said, chuckling.
"WHAT?!" the Wild Kratts and the fish-keteers asked.
"You were right. That law is clearly unfair, and should be excluded," Poseidon said. "So, as god of the seas, I declare that the Fish-keteers can go home whenever they want, for the Musketeer Law is cancelled."
The crew all cheered, not only because Martin could go home with them, but for the fish-keteers as well.
"Hey, D'Artagnan, why don't you go with us?" Aramis asked.
"Really?" D'Artagnan asked.
"Well, things are finally gonna be okay around here." Martin felt happy for the younger swordfish.
"We should celebrate," Jimmy suggested.
"Agreed. And I guess I have an idea," The Kratt in blue said.
"Woo-hoo!" the crew cheered, being carried by the swordfish.
"Don't think you can make something inspired on this, Aviva," Martin joked.
"Oh, yeah?" The inventor stood up on Porthos's back and pulled out her screwdriver, challenging Martin. "And I think you can't defeat me."
Martin summoned his sword. "We'll see about that."
They started a friendly battle, as the rest of the crew watched and laughed.