Author's Note: Hopefully this first bit doesn't feel too much like a recap of what you already know from the show. I had considered quickly glossing over part of the conversation where Clarke explains what happened after Lexa's death, but I really wanted to explore what that interaction would be like for them as Lexa learns about everything. Stick it out and you'll be getting some new backstory pretty quick, including the origin of those dastardly zombies and my own conspiracy theory for ALIE in the show. I really enjoyed crafting this chapter. Buckle up and put on your thinking caps, because this one is loaded. [insert diabolical laughter] Enjoy! ;)

"Okay, you've forced me to be patient long enough," Lexa announced as they settled up in a new tree. They had gathered enough food and water to get them through several days before heading back into the had both agreed minimal talking was best as they foraged so they could focus and avoid drawing unnecessary attention to themselves in case there were were walkers nearby. After several hours they decided to rest and finally have the talk they both needed.

Lexa was thoughtful as she adjusted to a semi-comfortable position on a branch. "So, Clarke, how long did you live?"

Clarke glanced up, seeming to search the sky for her answer. "Let's see, I lived for fifty-six more years after you."

"Fifty-six?" Lexa asked in disbelief. "That's incredible. So you lived to be seventy-four? No one ever lived that long."

Clarke chuckled. "Well, the life expectancy started to increase over time."

Lexa smiled. "I'm sure that was in part because of you and your mother as healers."

"I'd like to think so."

Lexa cleared her throat and looked resolute. "Alright, tell me what happened after... after I died. Did my spirit choose Aden as the next Commander? I don't have memories from being in the Flame - no memories of the Commanders who followed me. Did your people give up your chancellor and end the blockade? Did Titus keep his vow to protect you? What did you do?"

Clarke held up her hands in protest. "Whoa, there. Let's just take this one question at a time. Or, better yet, how about I just tell you the story of what I know - what I experienced - and you can ask me questions along the way?"

Lexa smiled bashfully and nodded. "Sorry, I'm just anxious to know what happened." She brought Clarke's hand to her lips and gave it a soft kiss. "I'm listening."

Clarke smiled back as she gave Lexa's hand a quick squeeze. "Whew, okay. Let me see... So, after you died things immediately started to go downhill. You remember Ontari, the Azgeda Natblida who was raised by Nia?"

"Yes."

Clarke took a deep breath. "Well, she stormed back into Polis, and... It was horrible, Lexa. She killed all your Nightbloods in their sleep the night before the conclave was supposed to begin and took the throne."

"What?" Lexa demanded as her nostrils flared. "That abomination cannot stand. That is not the way of my people." Her voice softened, sounding deflated. "My spirit surely could not have chosen that."

"It didn't," Clarke reassured her, then held up a hand at Lexa's questioning gaze and chuckled. "Wait, I promise I'm about to explain it all." She pondered for a moment, deciding the best way to describe everything. "So Ontari was the only Natblida left, but I knew what she did was wrong and that she would make the world a living hell if she became Heda. So... I decided to steal the Flame - the spirit of the Commanders."

Lexa gasped. "You what?!"

"I went to Titus' room to take the Flame. I didn't exactly have a plan for it, but I just knew I had to get it as far away from Ontari as possible. But Titus was there and confronted me when I tried to steal it. And that was when I remembered you talking about the eighth novitiate from your conclave. Titus told me it was Luna and that she was a coward and traitor to the spirit of the Commander, but he agreed that even she would make a better Heda than Ontari. So Titus actually gave me the Flame, named me the new Fleimkepa, and helped me get out of Polis while he stayed behind to face Ontari."

"And surely she killed him for that act of treachery."

Clarke nodded. "I don't know all the details of how it happened, but he died soon after, yes."

"And without the Flame Ontari couldn't ascend."

"Right," Clarke agreed. "She faced some grief from your ambassadors about that, but she shut them down and announced herself as the rightful Heda and took over control."

"And you searched for Luna?"

"Yes. I first went back to Arkadia to enlist Lincoln's help since he once told me Luna was a friend of his, but by the time I arrived, I was too late. Lincoln was dead - killed by Chancellor Pike for treason."

"That horrible man," Lexa commented, shaking her head.

"Yeah, but he got his comeuppance."

"What happened?"

"My people finally turned him over to the Grounders at the blockade."

Lexa grinned. "So our idea worked!"

Clarke chuckled at her enthusiasm. "It actually did! One of the few things that did go right." Her expression darkened. "But something terrible was happening in Arkadia that we didn't know about back in Polis. Even the people within Arkadia had no idea what they were dealing with."

"What was it?"

Clarke thought for a moment, trying to figure out how to explain it all. "Okay, so you, as Alicia - I'm sure you know all about artificial intelligence."

Lexa shrugged. "It's never something I've intensively researched, but I certainly understand the basic concepts."

"Good enough. Well, that's exactly what the Flame was, Lex. It was an AI that was implanted in the brain stem of each of the Commanders. It uploaded their consciousness into its memory, giving future Commanders access to the memories of the previous ones."

Lexa's eyes shot wide open. "No. Way. I was operating with the influence of an artificial intelligence? I don't know if I feel more terrified or stoked out of my mind at that idea!"

Clarke laughed at her geeked-out reaction while Lexa's mind was reeling at the implications. "So what does that mean, Clarke? Who developed the AI and how the hell did it wind up in such a primitive civilization?" She pondered for a moment, then nodded her head slowly as the realization dawned on her. "The first Commander? She must have been some kind of engineer, or scientist..."

Clarke nodded. "Yeah, that's exactly right. She... Well, she had a complicated past."

Lexa furrowed her brows. "I remember her name was Becca... But how do you know so much about her?"

"Along with the Flame was a book that Titus gave me. It was Becca's journal where she logged information from her experiments and described the purpose and engineering behind the AIs she designed."

"Wait, AIs?" Lexa questioned. "As in, plural?"

"Yeah, and that was the problem. The AI that was in you, the Flame, that was version two - the improved version."

"And version one..."

"...was what initiated the end of the world. The first apocalypse. And it survived the bombs and found its way into Arkadia."

"Holy shit," Lexa muttered. "So Becca, our first Commander, destroyed the world?"

"Indirectly, yes, but that was not her intention. She designed the first AI, which she named ALIE, in the hopes that it would help to make life better for humankind. Becca underestimated its ability to circumvent her instructions in pursuit of its own understanding of its core command to make life better. Becca was brilliant and had every possible resource at her disposal. She even had her own space station, which she fled to when she realized she couldn't safely create version two while even being on the same planet as ALIE. She understood then that ALIE didn't have the ability to truly interface with humanity and understand the wants and needs of real people. This second AI, the Flame, was different."

"So how did it affect me?" Lexa asked intently. "How much of me actually was me?"

"You were 100% you," Clarke reassured with a smile. "Titus said you were the wisest and strongest Commander who had ever lived, and that those traits were already part of you before you ascended. The Flame only serves to deepen and enhance the characteristics within you. So you were you, only with the added experience and wisdom of the leaders before you, which is pretty amazing, if you ask me."

Lexa just nodded, trying to process all this information. "Okay, I think I'm following you so far. Now this first AI, ALIE - you said she got to Arkadia? How? And what happened?"

"Man, that's another story that could take ages to tell, but here's the crux of it. My people lived up in space, right? And we only came down because our station, the Ark, was failing. We were supposed to be able to survive up there for another hundred years, and yet, it mysteriously gave out on us a century too soon. Well, turns out we had ALIE to thank for that as well."

Lexa gasped. "The AI that launched the bombs also brought down the Ark?"

"Yep. She knew there were people living in space when she launched the bombs and she worked for years to hack into the station's system. Her main motivation was to locate Becca so she could interfere with her attempts to replace version one. But when ALIE finally did get into the system, Becca had already returned to earth, her space station Polaris had been blown out of the sky, and every trace of it had been scrubbed from the computers. Because of all this, ALIE could find no record of her creator and just assumed she had not yet cracked the code for every computer system in the Ark."

"So that's why she wanted to bring it down?" Lexa could feel the gears spinning in her mind as she tried to put all these pieces together. "ALIE wanted direct access to your computers? Wasn't that a huge risk in case everything was destroyed on the way down?"

Clarke shrugged. "I guess that was a risk she was willing to take. Plus, it wasn't just for the computers. She also wanted us."

"What did she want with your people?"

"She wanted every last human being to join her City of Light."

Lexa's head tilted to the side. "City of Light?"

Clarke sighed. "Yeah. It was kind of this alternate reality. I still don't know exactly how it worked, but all you had to do was ingest a chip, which was similar in size to the Flame - only about the size of a quarter. When swallowed, the silicone chip would attach to the brain stem and block certain neural pathways and pain receptors. It would immediately stop the person from feeling pain, but it would also slowly remove any memories they had of pain of any kind, and eventually the people were just mindless bodies, simply existing to carry out ALIE's bidding."

"That's terrifying."

"Oh, believe me, I know. I watched it happen to my friends, my mom."

"Your mom?" Lexa's voice reflected the pain she could hear in Clarke's.

"Yeah. And then once ALIE had access to their minds, they were able to kind of mentally transport to this City of Light - this virtual reality without pain, hate, envy - which all may sound nice in theory-"

"But there has to be opposition in life," Lexa cut in emphatically. "That's what makes us who we are."

"Exactly. Which just goes to show how little ALIE truly understood the needs of humanity. She thought she would be saving the human race by getting every last person into this false world she had created."

"So could you tell someone had taken ALIE's chip just from looking at them?"

Clarke thought for a moment. "Not if you were just looking at someone, but if you talked with them long enough, you would know it wasn't their real self interacting with you. But what was truly terrifying was when a whole horde of them got together, blindly following ALIE. They just moved together in this huge mass hellbent on achieving the task at hand. It's like they were just animated bodies weren't really alive."

Lexa chuckled. "They don't sound too different from our walkers."

Clarke's eyes widened in surprise. "Well, shit. You just stole my punch line. And I had the story building up to that climax all planned out in my head."

"Excuse me?"

"You nailed it. These zombified, chip-faced Arkadians were the antecedents of our walkers of today."

Lexa's jaw dropped. "You can't be serious. Explain."

"Okay, so my genius friend Raven discovered what was probably the only way someone who had taken the chip could eliminate ALIE and her influence from their mind without having to die. She figured a way to send some kind of electrical pulse through the body that would fry the chip while leaving body tissue intact."

"But it didn't work?" Lexa was feeling more and more lost by the second.

"No, it did work, but we weren't able to cure everyone before it was too late."

"When was it too late?"

Clarke took a deep breath. "When we finally destroyed ALIE and her network."

Lexa nodded. "So the people who were still under her influence when she was destroyed..."

"It left them worse than before. We thought they might die, but instead they were permanently changed. Broken. Inhuman. We never knew exactly what happened to their minds, but the chip's frying effect left them fundamentally altered on a biological level. It was like they became hyper-focused on eliminating ALIE's problem: too many people. Killing people was their sole purpose. They were this mindless horde that spread like cancer - continually multiplying with seemingly no other cure than a bullet to the head."

Lexa was stunned. "So they became zombies?"

"Yep."

"And why do they go after the brains?"

Clarke shrugged. "I don't know. The way I see it, it's maybe a kind of recompense for what they lost - their own minds."

Lexa let out a soft whistle. "Damn. That's dark. Makes sense in a twisted way."

Clarke nodded and both girls stayed silent for a few moments, letting this collision of past and present fully sink in.

Lexa spoke again, "So how many zombies from that first generation got away without a bullet in their head? Have they been roaming the earth all this time?"

Clarke sighed. "It was so hard to know for sure if we had gotten them all. I think we did. All except for the one, though," she added with a sneer.

"What was the one?"

"Bellamy insisted we keep one to keep studying so we could try to find a cure on the off chance that there were any that had escaped and would be creating more zombies. I told him it was too dangerous and we shouldn't trust that everyone would keep it locked up. But more people sided with him than with me, though I was the chief medical advisor, so I relented. I had to admit I was curious to learn more, but I was more terrified of what could happen."

"And something did happen..." Lexa probed.

"It must have, but not as long as I lived."

"What do you mean?"

"That one zombie never got out as long as I lived, but I don't know if he somehow did afterward, or if there were in fact ones we missed all that time ago. I truly have no idea. All I know is that what I saw then is exactly what we're seeing now."

Lexa was shocked. "But how the hell did that thing live that long? You're telling me they can outlive us?"

Clarke nodded. "Seems like it, just based off of that one. And I can't really say that it outlived us - just that it took longer to die. I did observe its gradual deterioration over time. I think they're just very slowly decomposing, likely until they can't function anymore. But I really don't know for sure."

Lexa groaned as she leaned her head back. "So literally the only way to rid the world of the walkers in our lifetime is to kill them all. That is utterly impossible."

"I agree. The best idea I've come up with is that we need to carve out a safe space for ourselves. Build a wall and create a community for the few survivors we have."

Lexa sighed in defeat. "I guess so."

They sat lost in their own thoughts for a long time before Lexa startled upright.

"Hey, what is it? Are you okay?" Clarke quickly became concerned when Lexa didn't respond. She was just gazing off into the distance. "Hey, earth to Lexa!"

Lexa shuddered as she came back to consciousness.

"Another déjà vu moment?"

"More than that."

Clarke quirked an eyebrow. "What do you mean?"

"A very distinct impression. A directive."

"A directive? Lexa, what the hell are you talking about?"

"What happened to the Flame, Clarke?"

That caught the blonde off guard. "What?"

"The Flame. Where is the second AI now?"

Clarke stared at her incredulously. "Good grief, Lexa, that was more than a century ago! You see what that time has done to something as grand and immense as your tower. What do you think it would do to something so small and delicate?"

"You know where it is." Lexa wasn't asking.

"Perhaps." Clarke stared at her companion, trying to divine where she was going with this. "But I don't know for sure."

"Clarke, there's no time for this. I need to know where the spirit of the Commander is."

"Remember yesterday when you said you were petulant? It's coming out again." Clarke was trying not to show her frustration. She then realized this was less petulance and more Heda Lexa shining through.

Lexa narrowed her eyes, seeming to search for something within Clarke, who squirmed under the intense gaze.

"You had it last." Again, not a question.

Clarke was dumbfounded. "How could you possibly know that?"

Lexa shook her head and shrugged, some of the young girl in her showing again. "It's an impression. A very strong impression. I can't explain it. I'm feeling drawn to the Flame, Clarke. Like it's calling to me, and you're the only one who knows where it is."

Clarke nodded. "You're right. But I hadn't told you that part yet." She took a deep breath. "So I told you that Titus made me the new Fleimkepa and that along with the Flame he gave me the journal of the first Commander - Becca. Besides information about her research, the journal also detailed how the AI was to be used and implanted into the Natblidas, so I knew that I needed to find Luna and perform the ascension ritual myself."

"And you still found her in time, even though you didn't have Lincoln?"

"Yes. I remembered that when Lincoln first told me about Luna he had a map in his journal that would lead me to her. I told Octavia and she said he had told her about Luna as well, and that his journal was back in his cave, along with other books and maps that could prove helpful to us. So we found the map and finally reached Luna, but she was very reluctant to accept the Flame and ascend as Commander. She did not believe she was worthy nor that the people would accept her as their Heda. It wasn't until Luna finally saw Ontari ruthless and heartless in battle that she realized her becoming Commander was the worst possible option, especially as ALIE's influence was spreading like wildfire. The people had to be united once again to fight this common enemy, and she could see that Ontari was not the leader to accomplish that and never could be. So Luna agreed, I performed the ritual, and she ascended to Heda."

Lexa clutched a hand over her heart. "I am so proud of Luna. I just knew I couldn't allow Titus to hunt her down and kill her."

Clarke nodded. "Well, I can definitely say we were all grateful you didn't."

"Incredible," Lexa whispered. "And how long was she Heda? You must have been Fleimkepa for many Commanders since you lived for so long."

Clarke shook her head. "Luna was the only one. The last one."

Lexa's brow furrowed. "I don't understand..."

"So many people died to bring down ALIE and her army." Clarke's head dropped. "It was such a terrible time, Lex. If you were lucky enough to survive it meant you had to watch most of your loved ones die."

"And Luna died," Lexa stated sadly.

"Yes, only a few months after she ascended. And Ontari was killed just two weeks before that. We had searched and searched, but we could find no Natblida children. There were none still alive, so on Luna's deathbed she told me that although there was still hope for us to defeat ALIE, the Flame had not yet been able to fulfil its purpose, and I had to keep it safe. I thought she was going mad because without any Natblidas it would never have a purpose to serve ever again, but she made it seem like things were just being put on pause. I still wish I knew what she meant."

Lexa's face showed her utter disbelief. "The line of the Commanders ended so soon."

Clarke nodded. "I told you the world would have been lucky to keep you longer. But after ALIE and her minions were either cured or dead we set up our own democratic government to bring together the 13 clans. In my opinion, it's better to have only one leader if they are good and just, but when you can't guarantee that, it is far better for a group to be governed by multiple voices, so that's what we did. It took time, but the world did heal. We healed. Cities were built up and a greater sense of community was established. We built schools and hospitals, opened trade routes, and developed technology. Progress was slow, but it happened. The skirmishes between some clans never ended, but they were much more tolerable than they had once been. Life was simple, but good."

Lexa let out a long breath. "Wow. Thank you for telling me everything, Clarke. I still have so many questions about specific details, but I think I know all that I need to for now, so we're back to where we were earlier."

"And where is that?" Clarke asked. They had talked about so much that she wasn't sure exactly what Lexa was referring to.

"The Flame, Clarke. Take me to it."

"Ah, yes. And what exactly do you plan on doing with the second AI if we're able to find it at all? You think you're going to put it back in your head and rule the world?"

"Don't be patronizing, Clarke. I don't know exactly why I need to be with it, but I do. Maybe the close proximity will trigger visions that can help us." Lexa's eyes shot wide open and she even bounced a bit on her tree branch in excitement. "Oh, Clarke! What if the Flame will help me know how to end this zombie apocalypse? What if part of the Flame fulfilling its purpose is helping us now!"

Now Clarke was the one overwhelmed with information. "Uh, I don't know."

"Oh, please. Don't tell me you're a skeptic. With everything we've been through since we first met? Both in this lifetime and the one before. Surely you can't deny the power of both these AIs."

Clarke shook her head. "No, you're right. I can't deny that. I guess I'm just trying not to get my hopes up." Her expression became more steady. "Okay, I'll take you to where I hid the Flame. We'll have to go back towards Polis and-"

A sickening crash reverberated through the air around them. Both girls plastered themselves up against the tree to keep from falling off their branches in shock.

"Clarke, what the hell was-"

"There!" The blonde pointed behind her. Lexa turned just in time to see the source of another earsplitting sound as a massive branch from a neighboring tree plummeted to the ground, striking at least a dozen others on its way.

"Oh, shit. Shit, shit, shit!" Clarke's cursing snapped Lexa back to attention. She followed her gaze down to the forest floor and saw them approaching - walkers. Around twenty of them coming from all directions. They were attracted to the noise, hoping it was a death knell that meant dinner was served.

Author's Note: The idea that ALIE was responsible for the failure of the Ark is entirely my own conspiracy theory, not actual show canon, though I would love for it to be true. :) Thank you for all the reviews so far - let me know what you think of this chapter!