After endlessly searching for Annabeth, Percy decided to as the fish if they saw anything (because Percy can talk to fish) while Piper and Jason asked the other people that were at the beach. A few of the fish told Percy that they didn't see anyone who looked like how Percy was describing Annabeth, however one of the fish said he knew something. The fish told Percy to follow him. They were swimming for about a minute when the fish told him to stop. In front of him, floating, was a headband. Percy stared blankly at the headband but then realised that it was Annabeth's.
"N-no," Said Percy, "She has to be here somewhere. S-she couldn't have… you know… sunk."
"I'm Sorry, my friend," Said the fish, "Your friend is gone."
A tear trickled down Percy's cheek.
"Annabeth," He said softly.
After telling Leo, Jason and Piper the sad news, Percy said that he would be going to the underworld to bring Annabeth back to life.
"P-Percy," Said Piper while she was crying. "Ann-Annabeth is d-dead. There is nothing that we can do about it. Hades will never let us bring her back to life even though we saved Olympus.
"W-we can't lose hope," Said Percy, "I'll ask Hades to bring her back to life, if he says no then… well… we will find a way."
At that moment Percy couldn't take it anymore. He felt like his eyes would explode with tears so he just let it all out.
"Come," Said Leo in a quiet voice, "let's go back to camp."
When they got back to Camp Half-Blood, Percy convinced Chiron to let him go to the underworld and ask Hades to let Annabeth come back to life.
"But if Hades says no, then you leave right away, okay," Said Chiron.
"Okay" Said Percy.
He went to his cabin to get prepared for his journey to the underworld. When he was ready he checked on the Athena cabin. Everyone inside looked very sad. They didn't even notice that Percy was looking at them. He left the cabin and went to tell Chiron that he was leaving. However he heard Piper, Leo and Jason calling after him.
"What is it?" Asked Percy.
"We want to come with you," They all said.
"Fine," Said Percy.
And just like that, all four of them headed towards the river STYX to get to the underworld.