Hey everyone! Here is the promised guide and it's organized like this:

First will be interesting tidbits about the characters that didn't make it into the story.

After that, I'll talk about the development notes from each chapter.

Lastly, there is a FAQ based on questions I've received about the story.

But first and foremost: My beta for this story was my husband Dave, who put on a brave face listening to me talk and talk about this thing for three months straight.

Characters:

Bones (Agent Aster) - a Gaster!Sans and the first inspiration for the original one shot that is now the first episode. Frisk gave him the nickname Bones originally because he's all bones, but later evolved into giving him the same nickname as her favorite Star Trek character Leonard 'Bones' McCoy.

Because there isn't a Toriel in this world, there wasn't anyone for Bones to promise that he would protect a human coming through the door. The photo that was Bones' one hope through the years was the reason he didn't kill Frisk when he saw her the first time. Think about that for a minute: a human with a lot of LOVE walks through that door, of course the first monster in the Underground is going to attempt to kill them. Also think about how he must have also despaired that the human in the photo that he'd placed all his hopes in had so much LV.

Frisk (Agent Serif - because when Bones is alone, he's Sans Serif. Ha ha!) - Frisk's personality was based very heavily on Agent Carolina from Red vs Blue in the beginning of the series and is the inspiration behind C being an A.I. Frisk is a huge sci-fi nerd, a trait that she gets from her late father, though we only got to see glimpses of it through out the story. In my notes, Frisk's full name is Frisk Emily Church and the only time anyone every said it was Mob!Sans in a scrapped episode. Emily as a middle name was simply chosen from a popular baby names list and Church as a last name was a reference to her original inspiration from Red vs Blue.

Male Army!Frisk - His original appearance in the scrapped version ep. 9 did not paint him well and was before I decided that he would be the villain. When his Chara wasn't trying to mess with him, he proved to be very charming and considerate, though also very devilish in approach as seen with handing over his phone number while tempting Frisk with another kill for the night. He's just as competitive as his counterpart and, had he had his mind to himself, would have been a formidable foe. His A.I. really did squander what it had.

In my notes, his full name is Frisk Ethan Cross. A name meant to be analogous to Army!Frisk's.

C (Chara Dreemurr) - the Artificial Intelligence, who later outs himself on being the actual Chara, that lives in Frisk's head. That C was the original Chara was off the cuff while writing the reveal of the other souls, which was also off the cuff. In fact, most of things regarding C happened as a natural flow of the writing and had not been pre-planned.

Asriel - Asriel had a few character rewrites. I wasn't satisfied with him until I saw a piece of fan art for an adult Asriel that I can't find anymore (sadness!). The fan art depicted Asriel as a strong individual, one that was part warrior and all leader. There was a set expression to the eyes that I wanted to convey in words: Asriel as true king and a leader deserving of all fealty.

Asriel and Frisk are officially siblings. In Frisk's journey through the Underground, Asriel had to cut her shirt off of her after her fall for surgery and gave her one of his old striped shirts to wear. Which fooled whole bunches of the Underground, Asgore included, into thinking she was a child (since only children wear striped shirts). Even after discovering that she was an adult, Asgore still named her a member of the Dreemurr family. Though Asriel and his father have had their share of disagreements, Az is happy to have Frisk for a sister and refers to her as his family. I'm kind of sad that we didn't get to see Asgore in the story. In a scrapped draft there is a picture of him at Muffett's bakery celebrating his birthday with Asriel, Frisk, and Grace.

Papyrus - He turned out to be way more of a troll than I intended to start but it makes sense for the background I gave him and G!Sans. Paps just picked up the natural inclination to be a troll from the Gaster I wrote into the story.

Alphys - Alphys is only seen a few times in the story which makes me super sad. She had a major role in several drafts that were later scrapped.

Undyne - Only two appearances by the sexy fish? Oh man. I didn't intend that, but I wasn't going to shoe horn her into the story. Her first appearance was a great way to lampshade that she was well aware that her bestie and his brother would sometimes start acting and thinking like their original self. And that this was normal... well, for her at least.

Blue - The commonly used nickname for the Prime Sans. He directs agents from other timelines through a special set of cellphones he and his Alphys created to deal with anomalies.

White - I love the human theories for Sans! While I don't think they explain enough, I can totally see where it comes from, so I wanted one for the story. And every time White was in the fic, I desperately wanted nachos. I wrote several scenes with him and his Alphys. Their work life in the lab is a seamless friendship and they work with and around each other like its nothing. Unfortunately, all of those scenes were scrapped.

Red - Red saw so much development behind the scenes before actually making it officially into the story. See the chapter notes below for Ep. 9 for more info on that. He was my favorite character to write for during this series: when he arrived, he stole the show!

Bones said it best in Ep. 4 when he pointed out that Red was caring in unexpected ways to those he's given his loyalty. And it's plainly evident at every turn: his commitment to caring for his little sister; his relationship with his brother in which we see hints of his willingness to be submissive to Paps (even though it's played off as a joke); his friendship with Army!Frisk is obvious is each interaction. When Red loves someone, he loves them in the way they need it most.

One of the major themes (or Core Issues) of the story is understanding and it's played out thoroughly in Red's character. He understands what's needed and provides it, sometimes at great cost to himself. The male Army!Frisk desperately searched for someone that understood him by attempting to find copies of himself. Red and Army!Frisk's friendship was based on a deep understanding that while their experiences were completely different, the similarities in decisions made them two peas in a pod. My biggest concern with writing their relationship was showing how comfortable they were with each other without it coming off as romantic or sexual.

Cool side note: whenever I couldn't think of what Red would say in a certain situation, I would think "What would Aunt LeeAnn or Uncle Jim say right now?" And dang if it wasn't spot on! (My Aunt LeeAnn and Uncle Jim are freaking awesome!)

Fell!Frisk - Making a believable genius character wasn't as difficult as you would imagine. I read a lot of sci-fi and Ender's Game by Card is a great read if you want a look inside a genius child's head. Unmentioned in the series was her outings with MTT, who would take her to have her hair done, which is why it was different colors whenever she appeared.

An unmentioned bit from the scrapped original episode nine was that she worked clean up for her Grillby and would show up first thing in the morning after breakfast to help him get the place ready for opening. UF!Grillby even had a few lines of dialogue where he commented about how honored he felt that a member of the royal family was not just willing but happy to stoop so low as to help him.

Fell!Papyrus - While Paps didn't get as much dialogue time as I would have loved to give him, you definitely got to see that the kind of person he became post-Frisk. I went with the idea that Paps very desperately loves his older brother and fears his leaving, hence why he wasn't happy with Sans going back to the Lab. He does, on a logical level, understand that Red will never leave him, but centuries or more of living with that fear doesn't make it automatically go away post-Frisk.

He dearly loves Frisk and was the first to truly kneel to her in the version of the timeline I wrote for this story.

Fell!Gaster - Gaster here was meant to be every bit as disturbing as I could possibly make him. By having Bones and Frisk refer to him simply as Dings, I was attempting to indicate that they had known him long enough that calling him by a nickname was normal. My writing notes listed Gaster as having been angry that some random human child had been given his beloved wife's name. Until he met Frisk. The quote directly from my notes was "Lucida always wanted to have a little girl." He is very fond of his daughter and distinctly pleased that she loves him dearly. He's also smart enough to understand that he is incapable of raising her, hence leaving her to Red.

Agent Tahoma (Lily Williams): In my original notes on Lily, she had a huge crush on Asriel. I had even written a scene in which she and Alphys were staring at Undyne and Asriel on the training floor with double nose bleeds. This was later scrapped completely. Her later fangirling about Frisk was off the cuff. I wanted a way to show how the general population felt about something that Frisk often hid from.

Agent Franklin (James Foster): James being Frisk's childhood friend was completely off the cuff as I wrote his dialogue. His notes included a list of embarrassing things he knew about Frisk from high school which were available for classic noodle incident references.

Agent Niagra (Larry Rivera): Larry was my back-up character. If I came to a point in my writing with a role that needed filled, he would be the one to do it and so he became the sniper in residence when I needed a sniper.

King Chara - If you are a Triple A game dork like me, you recognized Chara's get up right away: the newest version of Dante from Devil May Cry. His powers are a reference to Yuri from Shadow Hearts. His possessiveness of his Frisk is not an indication of something abusive but rather a reflection of an earlier draft. In the original chap 10 draft, his Frisk was badly injured after an attack by MC, prompting Chara's willingness to join the good guys. He doesn't like to rely on people and when one of the two people (G being the other) that he gave his trust to was injured, he was ready to make a deal.

Mage!Frisk - If you are an obscure RPG nerd, you would have recognized this Frisk's look as Ellen from Folklore. In a scrapped episode, you would have seen a personality inspired by Alice Elliot of Shadow Hearts, another obscure rpg, and my second favorite game in the whole world. That's also where her long white hair and blue eyes came from.

G - G is the character I almost forgot. Originally, G was going to be a GoopySoul reference, was almost a reference to Fell!Gaster until I wrote him, and settled into the Sans I need to off set the edge of King Chara. I'd seen some artists do a very sweet faced G!Sans and I wanted to give that a place in the story. I particularly liked Fell!Frisk's mention that she'd call him just to talk.

Dragon Sans - D, as everyone started calling him, is based on the artwork of Roman-Kun on tumblr. I was dead set on having a dragon Sans break that front gate in spectacular fashion in the final episode. In an earlier draft, Dragon Sans was a summon from an AU I've been working on for a while with a mage!frisk. As the story developed, D naturally became the homage character you see in the story and Mage!Frisk became King Chara's love interest. I feel kind of bad saddling such a great Gaster!Sans with such a terrible Frisk though.

Grace - I wanted to introduce Army!Frisk's mom at several points in the story but it never came together or the character didn't work properly. She went through several name changes before I downloaded a most popular baby names list, pointed at the screen with my eyes closed, and her name became Grace. Her appearance is short, but I wanted to show that she understood her daughter's life and the danger it entailed, as well as a good relationship with Bones. In a scrapped draft of Ep. 3, before I had decided that Bones and Frisk would have more than just a very deep friendship, Grace had referred to Bones as her future son in law and was the person who suggested the new agents be 'saved from Frisk' on the training floor.

Chapter Notes:

Ep. 1 - This entire episode was inspired by Borouro's amazing art. It was the watershed moment of several years of writer's block.

Ep. 2 - St. Canard City is a reference to Dark Wing Duck, which I happened to be watching with my bestie and her sister while I was writing the episode. My beta wanted, as an addendum to this episode, a mini episode with Frisk, MTT, and Blooky having fun in town and for it to just be mad cap. I never had the inspiration to write it. I just couldn't see them getting into much trouble with wanting to make sure Blooky was happy and comfortable.

Ep. 3 - Grace, Frisk's Mom, was supposed to make her first appearance here and not in the second to last episode. But every time I tried to bring her in, it just did not work. She just wasn't the character I needed her to be. It wasn't until the development of the plot and specifics of Project Viper that she became the character I needed for her brief, but important, appearance in ep. 11.

Ep. 4 - I love steampunk and this, essentially fluff piece, was great fun to write. "The Pearl is in the River" is an old cliched spy phrase from tons of movies and it was fun to play with all the ways a 'pearl' could be in a 'river.'

Ep. 5 - Getting Fell!Frisk and her relationships to the other characters in Underfell right was super important for me. I also wanted her to be super believable because I had a feeling she would come back multiple times.

Ep. 6 - I changed up the narration for this episode, not because I was tired of Bones, but because I needed a third person style voice to narrate the story from. It was also a good time to let C have his one stage. The first draft of this episode was completely different from what you saw. Originally, Frisk confronted Riley directly and he pulled the mercs out and instead of the male Army!Frisk in her apartment, it was Riley. I really didn't like how that worked out and I didn't want the reveal of the past Frisk held so tightly under lock and key from coming out so soon. So I slept on it and when I woke up, the villain of the story was ready to go to paper.

Ep. 7 - I really like the idea of an Undertale set in the American Old West. I grew up in a place surrounded by the kind of folklore and regional stories you get from living in the middle of dust flats and lovely oases of trees and lakes. The roller skating intro came together after I took my little girl roller skating for the first time. Of all the fights I wrote for this story, the tentacle fight was the most fun.

Ep. 8 - Red vs Who? was an idea my beta had and it's potential for extreme hilarity made it a pretty easy write. However, the first draft was so short, I considered scrapping it all together. I'm glad I didn't. I wanted to do my own take on 'swap' and the idea that an Underfell style Sans and Papyrus would also be laid back surfers was too good to pass up.

Ep. 9 - Originally, I had written 9 right after writing 2. The entire episode had been written from Frisk's point of view and was supposed to be Red's first appearance. In the original draft, Red was very much the sweating, scared, obviously lost pre-frisk character that we often see in a lot of fics and art. It was also the first appearance of the male Army!Frisk before I had decided that he would be the villain of the story. After thinking about Red and what kind of person he would be when faced with the Frisk I wrote him, he evolved into the character we see in the story. And that meant an entire episode was scrapped from the series. What I wrote instead was the pivotal episode and the point of no return for the story. My beta literally jumped out of his seat reading it.

Ep. 10 - This episode started as a visit to G, Mage!Frisk, and King Chara's world, where visitors were physically changed from human to monster and vice versa, with Bones being human and Frisk being a chimera type monster. It was a total fan service episode that lamp shaded whole bunches of stuff from the Undertale fandom like monsters going into 'heat,' Bones nearly giving himself hypothermia and needing to snuggle, etc. It was funny and ultimately, scrapped.

I wrote an alternate beginning for this episode. It started with Bones and Frisk discussing Verdana's college tuition over a breakfast of crepes. I wanted to show that while they could not be parents in a traditional sense (Vivi is only a few years younger than Frisk), they did support Vivi, Rav, and their grandmother Carol financially. The breakfast was interrupted by Paps making off with his brother and Alphys for the Gravitational Waves announcement. Imagine G!Papyrus running down the hall with Alphys under one arm and G!Sans hung over his back like a coat, shrugging at everyone they passed.

Ep. 11 - Before I realized that I had hit my end game, I wrote about half an episode with the Undertale Mob AU. I was really proud of my depiction of Mob Boss Sans and no one will ever get to see it. Oh well.

Ep. 12 - The lab scene drove me crazy. I kept hitting a wall with it and couldn't figure out why. I slept on it and when I woke up (in the middle of the night no less) I had the scene together. Four hours later, I was very tired and I had most of the final draft together.

The crochet was happening! It was not going to escape! I tried so hard to put in ep. 5 and I couldn't make it work, but knitting Fell!Paps and crocheting Fell!Sans is my headcanon and it was happening!

Interesting note: I wrote the scene with the camera while writing ep. 8. I knew where I wanted the story to end.

FAQ:

Why doesn't your G!Sans smoke?

I don't like it so I chose not to use it.

Can I write/host/role play/etc. an Ask blog for Army!Frisk?

No. Absolutely not.

Who was your favorite character to write?

Red. Boney-hands down. Underfell!Sans was a riot and he had a lot to say in my head and my story notes that eventually made it into the story.

How did you stay inspired while writing?

I took a lot of walking breaks and once the weather warmed up, running breaks. Fell!Frisk's kidnapping played out in my head during a run.

How did you keep all the characters straight?

I gave them all very strong, unique personalities, memorable motivations, and kept notes on them all over my drafts. Then I wrote them over many drafts. One of my fav tricks for getting character personalities down is to 'take them on vacation' in my head, see how they act at their most relaxed so I know how they act at their most stressed. Frisk spent a lot of time sharing a hot tub with Kcalb from the Gray Garden in the 'vacation destination' in my head. No, it wasn't sexual. Seriously, it's Kcalb. He's not doing anything other than reading and eating as many sweets as he can manage. And Miss "I'm-too-reticent-to-even-tell-Bones-what-I-need-that-Gaster-has-to-do-it" wasn't up to shenanigans either.

Was writing a relationship between a monster (Bones) and a human (Frisk) weird?

Not really. And I don't mean that on some weird kink level. Frisk, as mentioned by Bones, only feels attracted to people that she has a deep emotional connection with. So she wasn't attracted to a skeleton per say, as much as she was attracted to Bones himself. The weird part was remembering to write in the obvious bodily differences between them. My beta didn't like it though.

How did you write the fight scenes?

Fight scenes were hard for me until I read one great piece of advice: "Watch a fight scene. Describe what you see." After watching a bunch of fight scenes and writing down what I saw, I was able to start putting into words what I saw in my head. The tentacle fight from 3:10 to Snowdin? I watched a fight with a grappling hook before writing it.

Did the male Army!Frisk get everyone out of the Underground?

That was part of his problem. He got everyone out... except Asriel. That's why he kept resetting. He kept trying to save Asriel and failing because the A.I. would kill him when Frisk was too weak to resist the influence. His world isn't actually in shambles. When we see it in the story, it's several hundred years on. Anyone who was still alive has left the area, hence it becoming farm land. The male Frisk was using the home he felt most comfortable in in the future. Remember that Fell!Frisk said that they traveled through time to get to the AU. His Papyrus figured out how to move forward and backward along his timeline but could not figure out how to move his brother through it, meaning that Dragon Sans had to live through all that time the regular way. What this means is that everyone he knows and loves is still there. It was important for the A.I. to keep him away from the monsters he set free because he was very proud of saving them and it gave him peace of mind.

Why you use they/them pronouns for the Prime Frisk?

Because the Prime Frisk has, over every reset, been every Frisk. I wasn't using they/them pronouns as a statement of any kind. I was being literal.

Any chance of a sequel?

I don't know. I'm taking a break since this has been three months of my life. I turned my husband into an Undertale widower and my children into Undertale Orphans! Not that I think my two year old noticed. My six year old had a lot to complain about though. I have some ideas kicking around in there though I'm not sure if I have something concrete enough to really get a new story together. I am thinking about it. Both Army!Frisks and Fell!Frisk are having a hot dog stacking contest in my head right now and it's really entertaining.