Nico returned with the other demigods a minute later, minus Reyna, but by that time, Percy had already stopped moving.
Jason got to them the fastest, being able to fly. He was holding his sword, ready to fight. Annabeth looked between him and the nearby River Acheron, and hoped her idea would work.
"Jason," she said. "The river-"
He got the message immediately, dropping his sword and lifting Percy into his arms in one smooth motion, and taking off just as quick. Annabeth could only watch from afar as Percy was submerged, hoping at this point the water would do what she knew ambrosia couldn't.
The sun was almost behind the horizon, lighting the clouds on fire and casting large shadows. She'd thought they were out of danger now, just for a moment. But the more she looked at the peaceful river, with its delicate ripples reflecting the bright orange sunlight, the more it resembled the Phlegethon.
She didn't know if she was strong enough to ignore the constant reminders of Tartarus, or for how long she'd have to deal with them. But she would let it eat at her mind forever, as long as she had Percy by her side.
Everyone's eyes were on the river, but Annabeth found herself drawn to the weapon Jason had left behind, as Nico stood idly by with the others. Nico had given her no explanation, and she'd seen no other attacker. None at all.
She felt her insides bubble with rage, as the only possible explanation crept up behind her. Any panic and conflicting thoughts faded away, as if being pushed aside. Until one thing was on her mind. She grabbed Jason's sword.
He never saw her coming. Until her blade was at his back.
Nico's hands slowly went up, as the others' attention was gathered.
Hazel was horrified, but didn't move to stop her. "Annabeth, what do you think you're doing?"
"Let's ask Nico."
Nico turned to face her, eyes glued to the end of the sword, which moved to his neck.
"I don't know what you think happened-"
"I think it was just you and Percy out here."
Jason marched forward, a hand raised, ready to blow Annabeth across the hill if he needed to. "Let him talk, and give me my-"
Annabeth locked eyes with Jason, and he suddenly stopped. She didn't know why, but it felt as if they'd connected, like they were in sync. Like there was a clarity between them that wasn't shared with any of the others. He wouldn't do anything she didn't want him to.
He lowered his hand, and backed away, keeping his mouth shut. Annabeth turned back to Nico, who, despite having a sword at his neck, seemed more confused than afraid.
"I'm not unreasonable, Nico. Just tell me what happened. Tell me who did it."
"I don't know."
The tip of the blade barely pierced his skin. Hazel started forward, but Jason put an arm in front of her.
"That's not good enough."
Nico glanced around, nervous and panicking, probably hoping anyone else would back him up. But it was Nico or Annabeth. He knew who would win that contest.
"You can't seriously think that I- Annabeth, I would never-"
Annabeth glowered. "You've betrayed him before."
Hazel was ready to act, but Annabeth was too close to Nico, and so was her weapon. "I know Nico, he wouldn't-"
"Do you?" Annabeth made eye contact with the rest of the group. "Do any of you? Because it's been four years since I met him, and he's still a goddamn mystery to me."
Nico kept looking at Jason, as if he were pleading.
Annabeth's fingers twitched, as if there was a homicidal ghost lurking inside her, urging her to make good on her threat. She'd always tolerated Nico, who was always lurking in the dark, whose motivations were never clear. "Too many secrets, if you ask me."
Hazel spoke on Nico's behalf, again. But this time sounding unsure. "I know my brother, Annabeth."
Annabeth felt her grip on the sword's hilt tighten. It felt like her fingers had turned to stone, or ice. There'd be no turning back now. "Then tell me what happened."
"You know I can't-"
All Annabeth had to do was push a little further- it would only take a second, and he would be gone. Nico fearfully looked into her eyes, as if he knew that too.
"I've seen the way you look at Percy. For years. I can make whatever problem you have with him, or any other problems you have, go away real quick. So you can either prove your innocence to me, or leave, and never come back."
Nico backed away, into the shadow of a nearby tree, and Annabeth let him.
Hazel ran forward, but he motioned for her to stop.
"Stay here until I return."
Nico stared back at Hazel, intensely. With his imminent death postponed he appeared not quite unafraid, but also as if he knew something the others didn't. Why he didn't say so now, with Annabeth ready to skewer him, she didn't know.
He disappeared into shadow.
Annabeth tossed Jason's sword aside, confident Hazel wouldn't try anything, and walked to the edge of the river before sitting down.
Hazel followed her, eyes welling with tears, obviously extremely upset. Nico was her brother, but Annabeth was also her friend.
"What are you doing?" Hazel's tone was accusatory, but it was clear she wouldn't fight her.
Annabeth stared into the water, where she had seen Jason lay Percy.
With the light of day waning into shadow, it seemed more like an abyss. She could almost imagine herself fading again, wearing the Death Mist, as she and Percy dove into darkness toward the Mansion of Night.