Between a line and a segment lies a ray, a piece of space that is open on one end and closed on the other.

The first time they talked about it, Piper didn't cry. She wanted to, and felt the burning in the backs of her eyes from the salt and the sheer will that she wouldn't shed tears over it, so she went to the climbing wall and scaled it, over and over again, until the muscles in her arms were shaking.

Jason sat and turned the shirt over in his hands, wringing it and winding it, caught up in thoughts of 'why' and 'how could she's'. When the thoughts had stewed around to where his mind was a storm and the poor shirt was wearing and flannel-y from being twisted around, he stood and tucked the shirt into his pocket, needing to leave but unwilling to part with it.

Jason turned out of the door of the Jupiter cabin and went for cabin six, where he was hoping Annabeth would be, as she was occasionally when she needed a place to stay, when she was working on Olympus or something happened to her apartment, be it massive water explosion or invasion of zombie rats (that had been bad).

Jason knocked on the door, feeling very small and insignificant in a way he wasn't used to, because he was a son of Jupiter and, despite never wanting or having asked for it, he was used to being the largest, the most powerful, the undefeated.

Yet he'd been brought to his knees by a smile at someone walking, a wink in the direction of the Ares cabin, a shirt he recognized that didn't belong to him that was gracing the form of the girl he loved.

He loved Piper and he needed Piper, but Piper needed more than him.

"Is Annabeth here?" He asked the girl who answered the door. She was lovely, with short curly hair and gray eyes like a beacon, declaring her a child of Athena and not someone to challenge to anything involving intelligence. In another life, she would have been pretty, and he would've flashed a smile or asked her name. But this wasn't another life, it was Jason freaking Grace's life, and he was crumbling because he had everything he ever wanted.

"No." Jason looked away, thinking he'd call her or something, but the girl laid a hand on his arm and said, "Do you need some help?"

Jason met the gray, wide-set eyes, looking up at him innocently, and uselessly wondered what Piper would think if he were to want something more than advice from this girl, before remembering that it didn't matter, because he didn't and Piper had no room to judge him in this area.

"Yes." Jason breathed.

"Let's go for a walk." The girl suggested, and when Jason asked her name she looked at him sidelong and told him it was Gabrielle. Then she asked if his problem was tied in to Piper, and he felt tight in his chest, because it was looking more and more like he was the only person who didn't know that Piper was loving other people.

And that was the worst part of it: he could have handled her cheating if she'd been sleeping with him, them, but it wasn't about the sex, it was about the love, and it was about her curling up with them when she got cold because she was used to the heat of the desert and her laughing at stupid jokes for the love of laughing with another person.

Jason nodded and looked away, his eyes habitually seeking out the Aphrodite cabin and snapping away before he saw her, because he knew what he'd find in her eyes: sorrow, hurt, love, acceptance.

Jason looked back at Gabrielle, and smiled humorlessly. "She loves someone else. A couple of someones, actually."

"She still loves you, doesn't she?"

"If she does, why would she need others?"

Gabrielle sighed and sat down on a bench. Jason joined her in pretending to watch the Apollo cabin playing basketball, going over Gabrielle's question.

"She's a daughter of aphrodite, right?"

"Yes."

"She must love you a lot."

Jason started to say, 'she does', but found the words sticking in his mouth.

"Do you think she could ever love just one person, though?" Gabrielle asked, calmly. The way she was talking was like teachers Jason remembered from school, like she knew the answer but was trying to get the student to come to the conclusion on his own.

"No." Jason thought of Annabeth and Hazel and Leo and Percy, all of whom Piper loved a lot. Then it was a natural link to think of her loving more people than just him romantically, which meant breaking up, stopping whatever thing they had that made him happy in order to make her happy, which he'd do if he needed to because her happiness was the big thing here.

But, earlier, when he'd been feeling betrayed and had started to say "we're finished", she'd looked wrecked. She'd looked like if he finished the sentence, she was fall into a little pile of baggy jeans and borrowed shirts and never stand up again. She'd looked like he was about to break her heart, which was ridiculous, because he was the one being broken.

Because clearly she wanted other people, because he wasn't enough for her, but there was no one other that her he wanted. There wasn't a person out there that made him feel happy and stable and gave him the ache in his heart that was so precious, intense, a bridge of pleasure and pain like when you come in from the cold and your skin starts to warm, gradually, burning as it's not used to the heat and isn't differentiating between a gently warmth and a painful burn.

Jason heaved a deep breath and tucked his head down between his knees, in the position he knew to be helpful for panic and being lightheaded, but maybe could help for his stress and heavy-heartedness.

"Have you ever taken geometry?" Gabrielle broke the silence.

"What?"

"Humor me."

"Um, I think so. I don't really remember it, though."

"Okay then." She slid a pen out of her pocket and held out her palm, near his legs, where when he sat up it was close like a book.

She drew a line and dotted both ends. "This is a segment. It's a piece of line that's closed on both ends."

She drew another streak beneath that, ink bleeding into her skin and turning the edges a fuzzy purplish color, like a bruise. "This is a line," she drew little arrows on either end of it, "and it goes on, infinitely."

She flipped her hand down, out of room, and drew on the pale skin of her wrist: a piece of line that she dotted at one end and drew an arrow on the other. "This is a ray. It's closed on one end and open on the other."

Jason gently gripped her forearm and stared down at the straight lines of dark ink, marring Gabrielle's skin, and understood.

That night he sat Piper down and talked, for a long time, and they went to the bonfire together even though sitting that close was torture because there was still a lot of hurt on both sides.

In the weeks that came they worked out a system that seemed to function, to keep them both happy.

Piper loved a lot of people: it was just in her blood, that she saw a person doing something, saying something, saw the emotions and thoughts and the tiny twitches of character, and she thought 'let me love you, please?'

Jason never wanted anyone but Piper, and he was always her priority. No matter who else called, who else wanted dinner or a kiss or a shoulder to cry on, Piper held the phone to her chest and looked over at the blue-eyed boy and if he nodded, knowing that she loved more than he could ever bear or hold on his own, she'd lift the phone back up and say 'yes', and the ray reached a little bit farther.