It was in that moment, the moment when she knew that Delphine had betrayed her, that Cosima remembered her words to Sarah with a crystal clear sharpness. "We are your biological imperative now." There was no specific rhyme or reason as to why those exact words had made it through her spiraling grief, but, inexplicably, they lessened the pain. Something about knowing that there was someone out there who would help her no matter what. Or, at least she hoped.

Without waiting on too much fanfare, a decision came into her mind. Never one to be still for too long, Cosima stood abruptly, swiped at the tears gathering under her lashes angrily and headed over to the flat. Hoping that Sarah would be there.

Outside Felix's, she knocked and waited, slightly anxious. She heard a voice drift closer towards her through the door and mentally prepared herself for the admission of guilt that she had to give.

The door pulled open and Sarah stood on the other side, looking at her. "Hey," Cosima said in a forced bright tone.

"Hey," Sarah nodded in reply, stepping aside to let Cosima in, her gaze drifting away from the dread-locked woman. Was that anger in her eyes, in the downturn of her mouth?

She stepped past Sarah into the interior of the room but turned around after a quick greeting to Alison. Sarah was just closing the door behind her when Cosima stepped up to her lookalike and began to explain, feeling rather pathetic, "Sarah, I... so should have listened to you about Delphine. I...," she looked up into Sarah's eyes, feeling in adequate. She felt nervous and shaky and there was more that she wanted to say, but with Felix and Alison in such close proximity, she couldn't make herself say anything else.

But Sarah met her gaze head on and nodded in slight assurance, filling in the gaps of her silence with words of her own. "You're alright," she stated quietly, her eyes staring into Cosima's, filling her with a sense of peace that she'd never experienced with Delphine. It made her instinctively raise her arms up and step closer to her counterpart. And though Sarah wasn't one for physical touch unless she was very close to them, like Felix, Sarah still let Cosima step into her arms and press herself into Sarah for much needed comfort.

When they broke apart, Cosima was sure she felt something shift in the air, but Sarah was seemingly too preoccupied with the pressing situation at hand. Letting Sarah brush past her, Cosima turned after she took a moment to collect herself, trying to capture the way that Sarah had made her feel so alive in such a short moment of time.

She sat down on a couch opposite to Sarah and pulled a paper from her bag. The one that Leekie had given her. Without a word, she set it on the table and pushed it towards Sarah, indicating the paper with a nod of her head when Sarah had cast her a questioning glance. "Leekie made me an offer," she admitted softly.

"A career at the Dyad Institute?" she asked in disbelief. Sarah looked over at her, like she couldn't exactly believe that Cosima was actually considering it.

"Uh, yeah.. studying us," she explained quietly, rolling the possibilities through her mind as she watched Sarah's reaction carefully. She inhaled slowly, intent on saying something else, but the intensity in the way that Sarah gazed back at her stole the words from her hyperactive mind. Finally, after several moments, she sighed and looked down at the paper, an unreadable expression on her face. Was it fear? Anger? Disappointment that she would go right back to the science so soon after Delphine had betrayed her?

She didn't look away from Sarah's face, now studying the paper the way she had studied her, until Alison came back with wine and a question about what her plans were. She answered Alison's question, but directed her words at Sarah, trying to get her to understand that she still wanted to help. That she would, in Sarah's words, stick to the science, and not get sidetracked again by wandering emotions. "Maybe I can help us best from the inside," she suggested, a slight question raising her inflection. And while she intended for her words to go out to the room, she could barely keep from looking at Sarah, looking for her approval. At her statement, Sarah dropped the papers onto the table in front of her and stared straight ahead, annoyed, but not enough to let on to anyone in the room. Unless they were looking for it, of course. Maybe if I hadn't gotten tangled up with Delphine so quickly, Cosima thought as she studied the tight lines around Sarah's lips, Things might've gone a whole lot different.

"I want to know what you're going to do," Felix piped up softly from the counter behind them.

Sarah shook off her concealed annoyance so fast that Cosima had to ask herself if it was really there in the first place. "Well, I can't trust this Rachel bitch, can I?" she stated obviously, but her eyes skimmed over to Cosima, as if to get her opinion before she made any major decisions.

An opinion which Cosima was more than willing to give. "Not if Kira's the first child of a clone," she said quickly. Your child, she added on silently in her head. She continued on, passing off her eagerness to help Sarah as just her love for science, "Scientifically unclassified... she could be what Rachel is actually after." And I wouldn't want to see you hurt.

Cosima lost track of the conversation for a few moments, thinking about Kira and Sarah's love for the little girl. Though she had never seen the two interact, she had talked with Alison about it once, about the time that she impersonated Sarah. And she knew, from that conversation, that Sarah's caring for her daughter was intense and passionate and – something that Cosima wanted.

The thought was powerful enough to shock herself out of her own reverie just in time to catch Alison's glance as she talked. "If there wont be anymore spies in my life... if my kids are safe... I'm sorry, but I have to tell you that I'm inclined to take the offer."

"Yeah... that's.. that's totally okay. That's totally your choice," Cosima replied, her mind still on a fading image of her, Sarah and Kira walking down a sidewalk. Hand in hand. Laughing. Like a family.

"Yeah, no judgment," Sarah said softly, her eyes slipping off into the distance as she took in Alison's decision.

Right at that moment, Cosima's phone beeped and displayed – "Oh shit. Delphine just got off a plane," she said, her voice low with shock as the image of her family was shattered to pieces at the words displayed from her screen, "I need to speak to you." Emotions twisted in her gut, anger most prominent among them as she continued to stare in disbelief at the text from the woman who had betrayed her. From the one who had apparently loved her.

"Right. She wants to help, right?" Sarah spoke, her voice filled with tired frustration as she stood and slung her jacket over her shoulders, "Just like Art and Paul and Rachel and everybody wants to help." Cosima watched her tug her jacket on and flick her hair out from under the material as she continued, "We make our own decisions, but I wouldn't trust anybody."

Cosima let her eyes fall back down to her phone, staring at the message from Delphine as Sarah headed for the door. Just as she removed the screwdriver and pulled the door aside, Cosima pressed a button so that her screen went blank and rose before Sarah could shut the door behind her.

"Sarah, wait," Cosima called, earning a slightly startled look from Alison, which she ignored as she hastily gathered up her coat in one arm, depositing her phone in one of its pocket. Sarah turned and paused just outside the door while Cosima hurried up to her. "Can I talk to you?"

"Yeah, sure," she nodded, stopping and looking at Cosima with her hands in her pockets. She hadn't shut the door to Felix's loft.

"Alone?" Cosima insisted quietly, glancing at Felix, who looked back at the pair of them with interest and slight suspicion. Alison had moved further into the room, presumably to gather her things so she could head straight back to the house.

Sarah gave Cosima the same look that Felix had given her, but complied by shutting the door and walking further down the hall. "Okay. So?" she asked abruptly, not to be rude, but because of her desire to get back to her daughter as quick as she could.

So Cosima, after taking a quick breath that really did nothing to steady her nerves, dove right into the conversation. "The science," she stated, then forced herself to elaborate when Sarah did nothing but raise an eyebrow at her, "You... you told me to stick to the science, Sarah. But I didn't. I let my emotions get away from me. And I don't ever want to let that happen again."

"Cosima, it's fine," she replied, stepping away from Cosima slightly, obviously wanting to get going.

"No, Sarah, it's not," Cosima exhaled sharply, fighting the threatening tears as she closed the gap between them again. "I never meant to fall for Delphine. She... she was all wrong for me and I knew it from the beginning." Sarah said nothing but she hadn't moved from her place so Cosima forged on in desperation, "You know, I remembered something about that night."

"What night?" Sarah replied, her voice bordering on disinterest. Whatever her crazy, geek monkey science friend was up to, she wasn't in the mood for it tonight.

"The night you first brought me the briefcase. Something I told you that night came back to me after Delphine betrayed me to Leekie." Sarah cocked her head sideways in slight curiosity now, her glance telling Cosima to continue, "I told you that we were your biological imperative. That you couldn't run away from the situation," she explained, taking a moment to ensure that Sarah was following her train of thought back to that night. Sarah nodded, her impatience finally falling away as Cosima caught her full attention. "But that's not what I meant, Sarah," Cosima murmured, taking a moment to notice how close they'd gotten. And how Sarah hadn't backed away.

"And what did you mean, Cosima?" her voice was light with curiosity, but layered with something deeper underneath. Something that caused a chill to run down Cosima's spine.

"I remember looking at you, that night, when you first walked into the bar," Cosima explained, looking into Sarah's eyes and noticed how they had darkened. Was that just from the lightening? Or... something else? Swallowing to shake the thought, she continued, her voice low and, without curiosity to pull it back up to its normal octave, there was no disguising the desire that laced her words. "I remember you sitting down and staring at the mirror, trying to wrap your head around it. Around us. Clones. And I couldn't stop looking at you."

"What are you getting at Cosima?" Sarah asked, and Cosima couldn't help but notice the repeated use of her name, taking a small moment to revel in the way it sounded as it fell from Sarah's lips.

"When I told you that we were your biological imperative, that you couldn't run away... I meant that I didn't want you to. You could've ran... but I didn't want you to go. And when I said "we", Sarah? I didn't mean any of the other clones. I wasn't talking about Alison or Helena or any other clone. I was talking about me Sarah. The other clones don't need you. But I... I do," Cosima explained in one long rush of passion, her hands, for once, moving only to cup softly around Sarah's face, pleased when Sarah pressed into her touch and let her eyes drift shut softly. "And I swear," she continued on in a whisper, "That if Delphine had never come into the picture, I would've been all over you to make crazy science."

"I don't do crazy science, Cosima," Sarah's eyes snapped open, but there was a smile playing around her lips as she tilted her head towards Cosima's, their foreheads touching gently.

"I dreamed about a family," Cosima amended quietly, curling her fingers into gentle fists and bringing her hands down slowly so that she held Sarah's chin gently between her thumb and pointer finger in each hand.

"Yeah?" Sarah asked, allowing her lips to touch Cosima's thumbs lightly as she continued, "Whose family?"

"Ours," Cosima murmured back. "You. Me. And Kira."

"Sounds nice," Sarah agreed with a hum that Cosima could feel through her fingertips. After a moment of silence however, she spoke up again. "But what about Delphine? She just landed. What are you going to do about her?"

"Well," Cosima grinned, letting her hands slide around Sarah's neck, her hands loosely clasped behind her as Sarah's arms naturally slid down around Cosima's waist. "She's not my biological imperative now, is she?"

Sarah laughed too, touching noses with Cosima now. "It's good that you can keep your sense of humor," she observed with a smirk of her own.

Cosima noted Sarah's cheeky use of the line that she herself had said to Sarah on that same night with the briefcase. "Yes it is," she replied and then neither of them said much more as they lost themselves in a long-awaited kiss.