AN: So this is my first attempt at Orphan Black, also my first crossover, so feedback is much appreciated! Set at the end of season 2 (contains spoilers if you haven't finished the season).

This was the last straw. She couldn't trust Delphine, and she couldn't trust Dyad. The problem was, without them, she was as good as dead. She was deteriorating rapidly and Kira's stem cells were no longer a viable solution. It would be another month before they could safely harvest any more from her, and she didn't have that kind of time. By her estimation, best case scenario she had half that. Half that before her body would give up on her.

And without Dyad she wouldn't have the lab, the medicine, or the research team to aid her in the search for a cure.

With the plan to rescue Sarah and Kira about to go down, she was rapidly packing everything she had access to but she was worried, that it wouldn't be enough, as she was in no condition to work on it on her own.

This was one problem her sisters couldn't help her with. Even if they had the knowledge or skills, they had their own problems to deal with.

They couldn't help her, she affirmed to herself. But who then could? Not Scott, he was still entangled with Dyad and that would put him in their line of fire. She needed time, without any distractions, and without having to worry about Dyad interfering.

Pondering her situation as she hurriedly left the building, she recalled an old friend who might be able to help. A childhood friend, and girlfriend, with whom she'd had intermittent correspondence with over the last 10 years.

The two had been best friends from the age of 6 or so, then later, in their teens, had fallen for each other. Cosima got lucky, her parents were very much left wing and liberal, and had accepted her orientation from the get-go. Karen hadn't been as lucky. Not by a long shot. Her parents were right wing extremists, absolutely conservative, they'd taken her coming out as God challenging their faith.

They took her to the Church and sought to have her "fixed" like there was something fundamentally wrong with her.

Suffice to say, that didn't work and afterwards her parent's had taken increasingly extreme steps towards curing her. In the end, Karen ran. It was the last Cosima ever saw her.

The Church and her parents searched for her long after she fled, more like a cult than a Church. Despite their best efforts Karen had successfully disappeared from even their radars. She'd reached out to Cosima about six months later, when she deemed it safe. She'd started a new life for herself in a big city somewhere. She'd found a job, a place to live, and was back in school, all under a new name.

Later, she'd gone into medicine, like she'd always wanted to do. She recalled from an old email that like Cosima, Karen had specialized in genetics. Something else as well, similar to her own course of Experimental Evolutionary Developmental Biology. But that was years ago and they hadn't spoken at all in 5 maybe 6 six years. Cosima couldn't remember exactly. Last she'd heard, Karen had joined doctors without borders, through which she'd met and fallen in love with a woman called Nadia.

A few years ago Cosima had tried to reach out through the email address she had, but had received an automated response that the email address was no longer active.

It was a long shot, but the best chance Cosima had, if she could find her. Cosima knew she'd assumed a new name, one that she didn't know, so finding her wouldn't be easy.

But she had to try, she decided, as she hailed a taxi. Cosima was the best chance all of them had at finding a cure (without Dyad), and this was her best chance to do so. She was no use to them dead.

She gave the driver Felix's address, as planned and then pulled out her clone phone.

She didn't know how to find Karen, but she knew someone who might be able to help.

Scrolling through her contacts she selected the one she wanted. Deciding a message was safer, lest the driver eavesdrop, she quickly typed her message.

It read "There's someone I need to track down, can you help me?"

His response was immediate. "Name?"

"Karen Beattie."

Again, the response was quick. "I'll let you know."

AN: As I said at the start, this is my first Orphan Black and first crossover, so please review and let me know what you thought. I had some troubles writing this, with trying to reconcile the fact that Lost Girl is fantasy and Orphan Black is sci-fi...