Daughters of Poseidon
You might have heard of Thalia, the daughter of Zeus. She's the one who gave up her life to save Luke, Annabeth and Grover. You probably know her as a barrier that protects the whole camp. Well, not all of it. She didn't protect a part of the camp, the place where you can see the sea. Someone else protected it.
Here's the real story.
Two months before Percy joined Camp Half-Blood
Under the sea, seven 11 year old children were being chased by a monstrous beast.
"Mermia, swim! Faster!" Serena screamed.
"I'm trying!" Mermia cried to her twin, Serena. Serena has blond hair while Mermia has brown hair. They both have blue eyes. Serena is a half piranha while Mermia is a half dolphin.
"Girls, swim faster!" Cory ordered.
"We're almost at camp!" Celeste cried.
"Girls, the monster's gaining on us!" Danielle shrieked.
"We're almost there!" Sasha Bella cried, running out of breath.
"Just a few swims more." Jessie Belle panted.
Sadly, Celeste's tail was caught in seaweed.
"I can't untangle it!" Celeste panicked.
Mermia saw that the monster was nearing.
"I'll distract him. Go. I'll catch up with you in camp." Mermia said, shakily.
"No, Mermia. He'll kill you." Serena said, worried for her sister's safety.
Mermia took out her knife and quickly swam towards the beast. "Go now!" she shouted as the beast followed her.
The six children quickly untangled the seaweed off Celeste's tail and swam to camp. When they nearly reached the shore, they turned around and gasped. Mermia was lying on the sand, her tail covered with blood. She was breathing heavily. The gods saw this and because of her bravery, Zeus and Poseidon found another way for her to live. A coral reef and a barrier to make sure nobody in Camp Half-Blood would die the same way. To protect all the half-bloods.
The beast kept trying to catch the mermaids, but no matter what he does, he can never get pass the barrier.
"Let's go." Jessie whispered as she and the others went to shore.
"No. I'm staying here. You guys go ahead." Serena ordered.
So Serena and the mermaids parted ways, hoping and praying they might see each other again. Serena disguised herself as a piranha and promised to stay with her sister for the rest of her life. But all of it will change and it will change Percy, Tyson, Serena and Mermia's life forever.