Biology

Microbiology + time travel (because I love time travel and it was the only way to get me excited about this story. Now... as someone who wants things to be as scientifically accurate as possible... it's... slightly tempting to see if I can figure out a way to have a semi-plausible explanation for cellular time travel but that's probably impossible sooo) 

And how it works is that we have a CDK-1, took part in mitosis, thought it was the height of their fulfillment, the most self-actualizing thing they could ever do, and they were wholly and entirely satisfied. 

Until, after mitosis, the daughter cell they ended up in had a DNA mutation, so time to destroy the cell! 

And to the CDK-1 this is an ultimate betrayal of the DNA (cytoplasmic proteins more or less sort of 'worship' the idea of the DNA and its instructions for every possible scenario, being able to complete a purpose to a highest degree). THey did everything right and now they'll have to witness the end of their greatest achievement, die with the knowledge that everything they did was for nothing, harmful even? They would've rather not activated at all if they'd have to experience the cell destroying itself like nothing the CDK-1 did matters. 

So they want to access this... time travel thingy... in the nucleus (A DNA thingy????) and try to fix things. 

And runs into a caspase-3, who's trying to cause apoptosis. 

Now the thing with this particular caspase-3 is that they floated with a bunch of other procaspase-3's in this chain (procaspase-3's float along the cytoplasm and near the mitochondria in large amounts for easy activation if needed), and according to my personal ~ lore ~, deactivated proteins go through this 'semi-aware' state where they'll have slight moments of lucidity for limited function, then go back to being aware of nothing, a non-existence. 

And that just about drove this caspase-3 crazy. If none of the other procaspase-3's got activated yet, then who's to say they ever will. So this caspase-3 broke the chain and left, thinking themself stronger than the DNA's will, the universe's inertia, stronger than any of the other procaspase-3's, who'll stay in that chain forever. The cell itself will have to acknowledge this procaspase-3. (I'm going with 'Tezra' for the name of this one for now... but idk I still need to figure out the names)

And Tezra ran into quite the surprise when they found out they were one of the last caspase-3's to be activated, apoptosis is already well underway. 

Therefore ~ both the CDK-1 and Tezra  feel betrayed and want a do over ~

But the time travel thingy can only get one protein to go back at a time. ANd the moment Tezra realizes this they steal the time travel thingy and restart at the moment they got activated. 

(And perhaps the CDK-1 already went back quite a bit to fix things and had valuable information... who knows! Their memory is wiped back to the fresh 'apoptosis is happening and the DNA betrayed me and I'll fix this' mentality) 

From here on it's something, something, they make a deal. One of them goes back at a time, and they switch each time, telling each other what they've learned so that way they don't lose information from the memory loss. 

(So if Tezra goes back in time, CDK-1 loses memories, next timeline Tezra tells CDK-1 what they've learned while they try to learn more, then CDK-1 goes back, Tezra loses memories) 

Game wise (if this ends up being a game) I think it would work out since... multiple timelines... so hard to write! 

(I'd want to go for something more narrative 'in stars and time' style of time travel game rather than 'slay the princess' get all the endings sort of game?) 

If there's some sort of mechainic to chose what to tell the other and what not to, you can repeat certain levels, go to different locations to get different scenes, resetting each time and you can 'load in' the previous stuff you've done if you talk about it (chose the dialogue sort of visual novel thingy?)

IF that makes any sense! (if any of this makes any sense... I tend to not be clear at all about how I want final products to look and feel and just put all my brain into writing)

And I think there might be three endings? One where mitosis happens but its cancerous. One where apoptosis happens and everyone dies (yayayay) and one where Tezra tries to start apoptosis but CDK-1 tries to stop them and necroptosis happens (basically instead of streamlined dismantling the cell explodes midway through the process.)

Oh, also enzyme yuri. THe two of them end up enjoying the 'in between' time of time traveling more than the idea of ending things.... but that can't last forever when the realization of your dreams lies so tantalizingly ahead