A/N: Okay, so this one mainly focuses on Mark and Cristina because that's what came to me. If you don't ship them, feel free to skip this one. I'll continue it at some point, though. Hope you enjoy :)

Guilt

A Blackstairs fanfic, by OTP-addict

As Mark ran his fingers through Emma's hair, he couldn't stop himself from thinking about how different it was from Cristina Mendoza Rosales's. While Emma's was pale gold–in some places white blond–Cristina's was the polar opposite, an onyx-like black. And while Emma's was soft as smoke, Cristina's was thick and unruly.

Stop it, he told himself. Cristina wasn't the one he was 'in a relationship with'. She wasn't the one whose hair he was playing with, she wasn't the one whose fingers were drawing circles on his wrist as he caressed her cheek lightly. That was Emma.

They were gathered in the kitchen, having just eaten dinner. An abnormal amount of demonic activity had been detected, and the 'adults' were currently planning what to do, how to act, while the younger residents of the Institute were minding their own business. Julian was pointing to a map on the table that Diana was bent over, Perfect Diego was standing, looking over Julian's shoulder, Emma and Mark himself were sitting at the table, and Cristina was sitting opposite them, next to Diego.

"So I was thinking," Julian said, "that since there was activity in a total of three locations, we would split up into three groups, one investigating here, another here, and the third here." He pointed to the map as he spoke.

"Good idea," Diana agreed.

"Who's with who?" Emma asked. Mark looked at her, wondering if she would ask to be put together with him. Probably not.

"Uh," Julian said. "I don't know, you with me, I guess?" It was no unusual request. They were parabatai, and as such they were stronger together, but Mark still noticed a tightening in Julian's jaw.

He had guessed that Julian and Emma were in love after Emma had come to him with her curious proposition. And ever since that revelation, Mark noticed every time Julian looked at Emma with longing, or every time Emma looked at Julian with guilt.

"Sure," she said, and no one who didn't know of the bond that was much more than platonic love would have guessed that she most likely dreaded having to face what she had done to her parabatai. Mark did realize that he was contributing to Julian's pain, but he also knew that it was for the best. He would rather see his brother hurt than stripped of his Marks.

"I'll go with Diana," Diego said to Mark's surprise. He had figured that Diego would want to go with Cristina, his maybe-girlfriend. Things were still unclear. "We have a few matters to discuss."

"Right," Diana replied.

"I guess we'll team up, Mark," Cristina said, smiling.

God damn it, Mark thought bitterly. God damn it all. But he smiled back and said, "Yeah, I guess so."

After cleaning up the kitchen, distributing the teams on the three locations, and dressing in gear for combat, Mark met Cristina outside the Institute. She was flicking a balisong about, folding and unfolding it skillfully. Her expression was almost bored.

Mark chuckled as he came to a stop before her. She raised an eyebrow.

"What?" she asked.

"Show-off," Mark teased, quirking a half-smirk.

"Psh, you wish you were as good as me," Cristina retorted.

Mark laughed, shaking his head. "Shall we take off?"

They ran into a pack of werewolves tearing apart a small cluster of Moloch demons, and were happy to assist in defeating them. When the fighting was over and the lycanthropes were thanked and bid farewell to, the wounds were attended to.

As Cristina drew an iratze and a blood replacement rune on Mark's shoulder, she suddenly said, "You know, don't you?"

Even though Mark knew exactly what she was asking, he still said, "Know what?"

Cristina gave him a pointed look. "If you don't know, it is not my place to tell you. If you do know, then you realize what I'm talking about, and you are just being a jerk."

Mark kept his face straight. "I know." Cristina was also keeping her face straight. He wondered what she was concealing.

"They're not very good at hiding it, huh?" she said, her voice carrying a slightly sad tone.

"Not when you know," Mark agreed. "Emma told you?"

Cristina nodded.

"When?" he asked.

She sighed. "A long time ago. Long before it even made sense to her. A time when she thought he didn't love her back." Her brow furrowed. The stele was limp in her hand, the runes finished. "Maybe it had been better if he hadn't."

Mark sighed as well. The situation was difficult, to say the least.

"She came to you?" Cristina asked, meaning their forged relationship, he figured.

He nodded. "I don't know if she thought she was being subtle, but it didn't take a lot of thinking to figure it out."

"Mhm," Cristina voiced her comprehension. "You sell it well, though," she encouraged. "At least on your part. I don't know about Emma–I think it's hard on her, having made that choice."

He nodded again. Despite himself, he noticed the rosy flush of her cheeks, the smooth, brown skin of her hands, the pink of her lips.

She met his eyes, and all previous thoughts were lost to him. It was a strange thing, this empty expanse of thought she induced. He had never experienced anything like it before her, not even with Kieran.

And then, amid the emptiness, a thought appeared. Was it possible that she felt the same way? No, it couldn't be. She was with Perfect Diego. And yet, before Diego's arrival, there had been a moment between them, when she had cut his hair and he had thought how lovely her gentle hands had felt against the skin of his forehead…

He didn't know how long they sat, looking at each other, but then, as he gazed at her face, a trickle of blood appeared at her hairline.

"You're bleeding," he said and brought his sleeve up to wipe away the blood.

Cristina touched her head gingerly. "Oh," she said. "I hadn't noticed. Is it bad?"

Mark examined her head. There was a small cut, most likely from a fall she had taken. "No, it's not serious." He leaned back and drew his hand with him, letting it linger ever so slightly on her hair.

She closed her eyes and sighed.

"What's wrong?" he asked, brow furrowing.

She didn't say anything. What he wouldn't give to know what was going on in her mind.

The Toyota pulled up next to them, and Emma and Julian got out. Emma immediately went to Cristina's side–Ouch, we're supposed to be dating, Emma, Mark thought.
"Are you okay?" Emma asked.

When Cristina opened her eyes, they were fixed on Mark's. "Yeah, we're fine."

TO BE CONTINUED.