Nico's heart stops beating the moment Rachel's footing fails and she begins tumbling through the air, right off the side of the steep snow-covered cliff and towards the ground far, far below. He swears loudly and curses his inability to do anything to help her. (Shadow travel - gods, why couldn't he have a more useful power?) He watches, frozen in fear, praying to whatever gods are listening - damn Zeus and all the damn silence - that something will save her.
The boy next to him - Justin... Jeremy... Jason! - tenses for a moment, then jumps off after her. Nico can only stare in shock before he remembers his companion is a son of Zeus (or Jupiter or whatever, but he doesn't have time to care right now), and the ache in his chest lessens just a bit (because nothing is ever certain, and he's becoming less and less optimistic as the days go by).
It's fifteen seconds - yes, he counted - before the two of them are back on the mountainside, Rachel shaking violently and Jason slumping against the wall of the cliff.
"Next time, you're staying at camp. I don't care what your crazy Oracle senses tell you." The words come out softer than he was trying for, all his worries and cares seeping into his tone. He hates it. "Got it, Dare?"
She looks straight at him with those bright eyes of hers and inhales sharply. Her hair is a mess, sticking up in odd places and falling in small strands across her face, and her clothes are a little torn from the climb up the mountain. For whatever reason, Nico thinks this is the most beautiful he has ever seen her.
"You don't have to tell me twice."