It had already been seven days. The quartet had traveled almost all the way Los Angeles; there were relatively minor monster attacks, and there were no more vulture-like creatures like with Marc. Marc, in stead, had accepted them to be sane and dropped them off exactly as he had promised to do. They were in pursuit of the Underground opening; during this whole time, Nico could've sworn he could feel the strange hag's 'powers' or 'immortality' while they got nearer and nearer to their destination. A cold chill overcame him at night, and goosebumps trailed up and down his arms. He wished they could reach their destination sooner, for 'his' memories. Thinking about it, he just ran in circles and his head hurt. So he didn't. He would just do anything to stop Percy from making that worried-sad-angry face. It didn't suit him at all.

"It's going to take us less than a day to get there," Hazel explained. "We're almost there, and we can meet Hades to try and convince him that his son's memories are literally worth a lifetime."Percy scoffed while Jason's gaze wavered.

"I doubt immortals have any idea what a 'lifetime' means," the blonde shrugged. The sky rumbled and they all looked hesitantly up. Percy spoke up, his voice wavering with fear, anger, or rebellion. Maybe a little bit of all. "We should get going."They all agreed with him.

"Yea, and we should IM Camp-Half Blood when we get the chance to. I don't think there is going to be any reception in the Underworld," Percy joked sarcastically. The others looked at him weirdly, although Nico's thin lips were twitching upwards slightly. "I'm just saying."

Meanwhile, in Camp Half-Blood, a certain daughter of Athena was contemplating the meaning of the prophesy. She knew with all to much experience how life-threatening and devastating the words from Rachel can be. Annabeth paced the meeting room of the Big House, her girlfriend's kaleidoscopic eyes following her ever-panicking movement. "Calm down. You're going to die before you get any white hairs. Stop worrying so much. We got out of the last one just fine, didn't we?" The offspring of Aphrodite put on a charming smile and tried to calm her girlfriend down but the blonde didn't listen. Piper almost thought of charmspeaking her but she would never do that to someone so precious to her.

"The lines of the prophesy, 'the hidden angel shall never resurface until the son of Poseidon retrieves the mace...'Hidden angel, hidden angel... Oh, oh gods."

Piper put on a concerned face and put an encouraging hand on the blonde's shoulder.

"What's wrong?"The daughter of Athena turned to the child of love.

"Piper, the hidden angel. Nico's last name is di Angelo... Hidden and resurface... His memories!" Piper considered this and soon came to understanding on the same level as her girlfriend.

"So, Nico will never get his memories back until son of Poseidon retrieves the mace... Percy gets a mace?"

"No, probably an favor from a god or goddess." she frowned. "There's no actual god or goddess with a mace, even in Roman mythology. But I did some research-"

"Like you always do," Annabeth ignored her.

"Lethe is actually a goddess, not just the name of a river in the Underworld. However, she has a stronger opposite: Mnemosyne. She is the goddess of memory, remembrance, language, words, sight, writing, and patron of poets. She is considered on of the strongest children of Uranus and Gaia. Her siblings include Kronus, Iapetos, Oceanus, and Hyperion. She is also the mother of the nine muses with Zeus." The blonde slightly rambled, getting a tab bit off topic before Piper cut her off with a light kiss and chuckle.

"Okay, so what does that mini history lesson mean for us?" The blonde's expression immediately darkened.

"That might be where Percy, Jason, and Hazel have to go to. There's a pool called Mneosyne, like the river Lethe, but rumors say that they're next to each other. We really need to IM then. Like, right now." In response, the brunette fished in her pocket and took out a golden drachma. "Let's just hope that we make it in ti-." the blonde stopped mid-sentence and stared off into the distance.

"Annabeth? What's wrong? Another history lesson coming up?" A moment later, Piper found herself against the wall with a dagger to her neck. "W-wha?"

"Hmm, the daughter of love. Yes, this will be quite, ah, fun."

"Anna...beth... What's... Wrong with... You..." Piper struggled against the hand crushing her gut against the wall as well as the dagger, but no avail.

"Don't worry. You'll be quite safe with me. As long as you obey her queen's wishes," Annabeth laughed, but it seemed more sinister, more evil. Piper was aware of a pain in her head and fell to the ground, seeing black dots dance in front of her. The last thing she remembered before black out completely were golden eyes, staring down upon her face.