Doesn't 100% fit in with canon if you think too hard about it, but I just kinda wanted to explore that quote from Isaac on Mars Lighthouse because I thought it was kind of a weird thing for him to say.
It took him almost a full day to notice that she wasn't speaking to him on the way back home from Prox. After thinking about it he was shocked he hadn't noticed it sooner, especially given their close quarters on the ship.
"Jenna, can I talk to you?" he asked, approaching her when she was standing on the deck apparently doing nothing more but staring out at the waves surrounding them. The others were spread out across the deck in a similar fashion, chatting idly amongst themselves.
"No," she said, and turned to walk away. He followed.
"Seriously, you're doing this? Jenna, you haven't spoken to me all day."
She kept walking.
"Jenna, seriously. If I did something wrong, I want to know what it was that made you so mad."
"I don't want to talk about it," she snapped, and the tension in her voice should have stopped him. But he was stubborn.
"Well, we need to. Whatever it is that's b—"
Suddenly, she whirled, punching him in the face. His hand flew up instinctively, Cure Psynergy already starting to flow from his fingers. She grabbed the hand and yanked it away, hitting him again with her other hand and shouting, "Don't you dare heal, Isaac!"
"Jenna!" Felix said, the shock in his voice evident as he started toward her. She threw a hand out towards him without taking her eyes off Isaac, fire flaring up around her palm.
"Don't, Felix." Her brother raised his hands in a surrendering gesture, pointedly taking several steps backwards and away from her. All conversation on the deck had stopped, and it was dead silent except for the sound of the waves on the side of the ship.
Isaac coughed, bringing a hand back up to his face to try and stop the bleeding from his nose, but didn't heal again because he knew she'd see. "What the hell, Jenna?"
"Why didn't you stop me?" She was still shouting, hands clenched into fists at her sides.
"What are you talking about?" he said, wondering how long he could go before the broken bone in his nose started to set that way.
"On the lighthouse," she said. "You said you knew what you were doing. You knew it was them."
"I... I can't explain it," he said, and she shook her head, eyes blazing.
"You're going to have to try."
"I don't know. I just had a feeling. They disappeared, the whole village of Prox couldn't find them. The Wise One needed an obstacle. It made sense." In the back of his mind, he was trying to remember what he'd heard about getting a broken nose. It was probably a bad idea to inhale the blood.
"So you knew even before we set foot in that lighthouse?" she said, and her voice broke. Guilt spread through him like poison in his veins, painful and slow.
"I don't know. In a way, I guess I did."
The tears started to roll down her face. "And you couldn't have warned me? Warned any of us?"
"I didn't have time," he said desperately, taking a few cautious steps toward her, dropping his hand from his face. "Please, you have to understand..."
"I can't!" she said, and she was gasping for air like she was being suffocated. "I can't understand! I watched my parents die twice, and it's your fault!"
"I know, I'm sorry." He was standing directly in front of her now, carefully raising his hands to wrap around her back.
"That's not good enough!" She was really sobbing now. He healed himself then, and although he knew she felt the Psynergy he used, she didn't stop him this time. Just raised her hand to pound against his chest. "How could you? Your own father—didn't you think about your dad?"
"I couldn't," he said, and suddenly he was crying too. His legs shook under him; he sank to his knees and she followed, still beating her fist uselessly against him. "I don't know. I'm so sorry. I don't know."
He felt utterly broken and useless and weak, sobs ripping themselves from his lungs as though they'd been trapped inside of him. And in the back of his mind he realized they had been. He hadn't cried since that day three years ago, and he was sure she hadn't, either.
They stayed like that, kneeling on the deck and holding each other and crying for a longer time than Isaac would have liked to admit. When he looked up, he realized that at some point the rest of the party had gone off inside of the ship and left them alone. Probably Mia's idea.
Jenna sniffled and sat back on her heels, then dropped to sit on the deck with her legs splayed out to the side. He mirrored the movement, rubbing at his face with the heel of his hand to get the blood and tears off his skin.
"I haven't cried..." he said, meaning to finish the statement off with something else, like "in three years" or "since then," but trailed off, and she understood.
"Me neither. I couldn't."
He exhaled heavily, leaning back on his hands. "I am sorry. I just...didn't know what to do."
She shook her head. "I know. It's okay. I mean... They survived. In the end." A small laugh escaped her, still sounding a bit like a sob. "I'm sorry I hit you."
"No, I deserved it," he said, laughing a little himself. He tilted his head back to look at the sky above them, as the sun began to set. They passed the next few minutes in relative silence, punctuated occasionally by a sniffle. "We should head inside," he said eventually. "The others are probably worried."
"Yeah, you're right," she said, making a last effort to scrub away the remnants of tears. He climbed to his feet and offered a hand to help her up. She took it, her left hand in his right, and stood. He started to head for the bulkhead door that led for the interior of the ship, but she didn't move, and instead only squeezed his hand.
He turned around to look back at her. "What—"
She stood on her tiptoes, balancing herself with her free hand on his shoulder, and kissed him on the cheek.
"Friends again?" she asked.
He grinned. "Obviously. Always."