Clarke stepped back so shakily that she felt Lexa's arms soon enclose around her. Clarke turned to meet her eyes that were full of concern.

'Who is she?' Lexa asked.

Clarke glanced at the body again, convinced that she was seeing things. She had visions of Finn after his death but why would she have them of Tsing? This thought was quickly banished when she realised that Lexa and the others could clearly see Tsing too. There was no way Clarke was imagining her and that thought did nothing to ease her nausea.

'It can't be.' Clarke stuttered. 'There's no way.'

'Is it a Mountain Man?' Raven asked, eyes narrowed and taking in Clarke's shock.

What had united Skaikru with Grounders was the hatred and fear of the Mountain Men. Only they ever caused such a reaction.

'That's Tsing. The doctor. The one who came up with the plan to use our bone marrow.' Clarke explained as she fought to regain control over her breathing.

Hatred pounded through her heart as memories flooded back of how ego-maniacal Tsing had been and her careful manipulations as the caring doctor. She could still remember the feel of the cage, the smell of Anya's body that had been so used, the look on Tsing's face when the Grounders reached out to her and she swept their hands off her hair and the disgusted look she had worn for them as though they were vermin.

'That's not possible.' Octavia said quickly.

'Clearly it is.' Lexa replied.

'But how? How the hell is she here?' Clarke stammered, still shaking and Lexa rubbed her arms soothingly.

'We can seek the answers later. We have to get out of the open.' Lexa urged and Clarke nodded, glad to get as far away from Tsing as they could possibly get.

Lexa led them through the streets and in the direction of the glowing light. They approached at a light jog due to Raven's leg and kept in tight formation. The earlier attack had confirmed all of their suspicions that they would not be able to complete this mission without a fight.

They entered the area where the light had come from to see that it was the sky itself that was giving the glow. Raven deduced that they'd need to work out exactly where to go themselves so they moved along the streets searching for anything familiar.

At the third street Wick found a door that stood out from all of the rest. Unlike the smooth polished doors of the rest of the city it was made of steel and there was a button to press. Clarke's unease grew; it could not be that easy. As Wick pressed the button though, no attack was launched and so they stepped inside.

They were back on the engineering deck. Clarke had been here several times with her father who had tried desperately to get her into engineering but Clarke's path had then been dedicated to medicine.

Raven and Wick immediately made their way over to the control panel as casually as if this was just another day on the Ark.

'Holy crap.' Raven muttered.

'Is this one of the places or not?' Octavia said, a harsh note to her voice and looking as though she would rather be anywhere else.

'Yeah, this is one of them.' Raven confirmed. 'Wick, get started on shutting this plant down.'

'On it. It'll take time though.'

'That's okay. They're not here yet.'

'Who isn't here?' Lexa said, her voice reflecting the danger.

'There's code that's showing activity. There's not just the people that took the chip originally. There are too many of them.' Raven said desperately.

'How is that possible?' Octavia asked.

Clarke thought she understood. She did, in her heart, the second she saw Tsing. She glanced to Lexa.

'Raven, you said you didn't know what defences would be activated to try to stop us and what weapons we'd face...'

'I know.' Raven said in a small voice.

'What is it?' Octavia asked, looking from one to the other.

'We're the weapons.' Clarke said fearfully. 'Lexa and I.'

'Holy hell.' Monty breathed.

'What is it?' Jasper asked, instantly by his side.

'The City of Light. It's full of people. Hundreds of them.'

Monty stared at the screen in shock. He had no idea where they had come from. None of the data was making sense. The only common connection was that the code was awfully similar to Lexa's and Clarke's signatures. At first, Monty thought there had been a malfunction and Raven had accidentally created a hundred Clarke and Lexa's but they were definitely distinct individuals.

'Okay, Lexa's a badass commander and Octavia is a warrior but how the hell are they meant to kill an army of hundreds?' Miller demanded.

'They can't.' Monty said.

'Clarke?' Lexa questioned.

'It's us.' Clarke said. 'The only thing that has changed in the City of Light is that we're here now. The Mountain Men never took the chips. They could not exist here before. If Tsing is here, I'm betting the rets of the Mountain Men are too.'

'Clarke, it's not like you could just wish them here.' Octavia said, looking at Clarke as though she was losing it.

'The plants were prepared.' Raven said. 'ALIE had access to all the nuclear missiles before. It makes sense that there would be some preparation in case an AI or a similar concept tried to interefere again.'

'So they used us?'

'The mini Flame works alongside the Flame. I'm guessing that Lexa triggered the defences once we set about this threat. That's how it has never happened before. The Flame is part of Lexa's blood. It takes on her entire being, her mind, her intentions and her memories and now it has yours too, Clarke.' Raven said slowly. 'I don't think that was really Tsing. It never had access to Tsing's being so it couldn't truly replicate her. That was your memory of her Clarke.

'Your memories are being used to create these soldiers which are basically fighting avatars. It's the ultimate defence to turn an attacker's weaknesses against themselves. You both have killed many people, the numbers alone and the guilt factor is probably being used to try to stop us.'

Clarke reeled. She and Lexa would basically have to conquer themselves, everything that had happened to them or burdened them in some way. Tsing was just the start. Clarke didn't want to think about what came next.

'I love it when they underestimate us.' Clarke muttered darkly.

'Guys, I'm in.' Wick muttered. 'I can shut this plant down but there's another one a few blocks over. Looks like it's in a subway station. Monty's found it by the looks of his messages. I need someone to go over there and activate the console and I can shut that down from here too.'

'I'll go.' Raven said.

'No,' Clarke said quickly, 'Wick needs you here to work through the systems. If we just need to activate it, with Monty's help we'll be able to do it.'

'I'll come with you.' Octavia offered.

Clarke glanced at Lexa. If what Wick said was true, then this room would be the first place people would likely attack. They needed a defence and Lexa was it. She was the best fighter. Clarke saw the understanding in Lexa's eyes.

'Octavia, stay here with Lexa.'

'No.' Lexa said, determination etched in her voice. 'You will at least need an escort. Their soldiers will be drawn here but it will be foolish to allow that to give you a false sense of security. They may well be keeping watch for other activity.'

Clarke took in a sharp breath, frustration gnawing at her. Lexa's face was resolute. She would not fail.

Clarke wanted to close the distance between them but she also didn't want to risk seeing Lexa's strong gaze falter. She needed to see her like this, as composed as the ultimate warrior.

'May we meet again.' Clarke half whispered.

'You'll see me soon.' Lexa vowed.

Hi guys. Just wanted to say a huge thanks for all your views and reviews. Hopefully you're enjoying the story so far! I know a lot of the season 3 content was repetitive but that was just about fixing JRoth's mistake and showing that Lexa could still be a part of the story and didn't need to die. Hope you've enjoyed the original content though as I kind of just picked up the threads from season 3 and went with it (and I apologise to any fans of characters I have killed off!). I do have a plan for beyond the City of Light storyline so I'll probably keep going with writing if the story is still being enjoyed.