AA-5100 probably wasn't the most exemplary of red blood cells, but she completed her deliveries on time and only got lost once—and that happened when she a rookie. Nowadays, however, she merely did her best to hurry along the blood vessels, be they artery or vein. Sometimes, whenever downtime was inevitable, she would find herself slowing down and watching the lives of her fellow cells at work. And sometimes, if she were lucky, she would get to see her mentee, AE-3803.

AA-5100 won't lie.

At first, she wasn't expecting much from the younger redhead. When they were both erythroblasts, it was rumored that AE-3803 was prone to getting lost and finding trouble throughout the bone marrow. Of course, it wasn't always her fault that she got lost (some erythroblasts could be needlessly cruel despite Miss Macrophage's efforts), but AA-5100 can't deny that her feelings were colored by the time her mentor assigned her to assist AE-3803.

Like her own mentor, AA-5100 tried her utmost to be as accommodating as possible. After a few trial runs, she found that the young erythrocyte was sort of getting the hang of things, and in the spirit of "broadening her horizons", the older red blood cell let her loose.

It was equal parts disastrous and wonderful.

Disastrous: AE-3803 managed to get attacked by a bacterium three times in a span of one circuit to the lungs.

Wonderful: well, now that was something that AA-5100 still had to discover if this was true.

See, while she had reservations about her newest charge, AA-5100 couldn't deny that the young erythrocyte had grown on her. In fact, after her initial realization that 3803 was more than willing to improve herself (no matter how long it took), she had taken upon herself to be always on the lookout for her mentee. Her positive outlook on life and the trivial troubles she managed to find herself in was all part of the package of such an endearing colleague. It was no wonder that after a while, the brunette erythrocyte found herself referring to AE-3803 as one of her closest friends.

That was about the time when she realized that 3803 managed to get herself wrangled up in a friendship with an immune cell of all things. Objectively, 5100 did respect them for their work, but she wanted them as a whole to keep away from her. All of them were weirdos who were bloodthirsty, manic, and lived in the shadows like they were a bunch of heathens—seriously, who does that? However, like most things involving her beloved charge, 5100 managed to warm up to the neutrophil—albeit, a little slowly.

The brunette kept her distance; she didn't always interact with the rather reserved white blood cell and honestly, it seemed that her friend didn't expect her to...which was all well and good. He was an enigma that 5100 couldn't puzzle out.

Why was he always so kind to 3803? Why was he always willing to show her around the body? Why was he so annoyingly, obnoxiously, and irritatingly so amiable and willing to help?

There had to be a reason why he was so unfailingly nice and dare she say it, charming.

His smiles were soft and pure. His eyes, usually filled with condemnation for virus ridden cells or bacteria, were filled with...something that she couldn't—wouldn't—name. And above all else, he was always there to save the day whenever 3803 was in trouble.

Overall, it was...disconcerting.

Their relationship, whether it was innocent or not, troubled her.

NT-4201 doesn't understand her mentor.

AE-3803 was older than her, far more driven, and supposedly far more experienced. Yet, she still acted like a young erythroblast newly introduced to the idea of delivering oxygen and carbon dioxide to specific parts of the body. Her comments about the job were always interspersed with questions, as if she didn't remember her role or where she was. Shadowing her mentor during that one circuit when the body was undergoing hypovolemic shock was so embarrassing, that when NT-4201 visited her friends, she didn't want to tell them about her disastrous first circuit around the body.

And yet, the dark haired erythrocyte learned something.

She learned that even when the odds were stacked against them—no, stacked against the body—the red blood cells were still tasked to their duty. Red blood cells were created for a purpose and that purpose was to deliver oxygen. Without that supply of this precious chemical, then no one could function.

They were needed.

To even suggest otherwise would have been ludicrous.

And yet, NT-4201 found herself doing that when she had struggled to trudge throughout the blizzard in the midst of such chaos. When she felt that the body was at its end, she lost all hope. During her classes in the bone marrow, they rarely touched the topic of what to do whenever the body was under stress. They only focused on geographical locations, the importance of the deliveries, and training to be physically fast and efficient. So, when faced with the reality that the body could end up dying, NT-4201 instantly balked at the idea of continuing their work.

What use would it be in the end? It certainly wouldn't have made a difference if just one red blood cell were to handle the deliveries.

Yet, her mentor believed in the cause. She believed in their duty. But most of all, she believed in herself.

There was no reason to suspect that strangers from another land would help save the day, nothing to suggest that there could be a happy ending. Much to NT-4201's utter disbelief, AE-3803 kept going. If it were not for the acceleration of the calamities within the body, perhaps she would have gotten a lot more done.

Maybe, if AE-3803 truly believed in herself, she could have single handedly saved the body.

Ha! Imagine that, a lone red blood cell saving the body when it was an immune cell's job to do so.

Still, NT-4201 doesn't have to question the "what if's" and the "what could have been's". The ideas were endless; possibilities countless to explore. After all, due to a gigantic pipe in the sky, a god had smiled upon them all and sent a fresh wave of their brethren (though very strange and unaware of local customs) to help carry out their duties.

And after that fiasco?

NT-4201 can't say for sure that she'll ever truly consider her mentor to be a friend, or even a close acquaintance. The redhead was mildly irritating and the lack of attention to details in her surroundings were off putting. One thing, however, the dark haired erythrocyte can grant the airheaded cell is that she's very kindhearted and resolved.

Those are traits that are common among red blood cells and the normal cells, but definitely not necessary in their line of work. They're supposed to be fast and efficient. Nothing more, nothing less. Such flighty emotions and scatterbrained tendencies would have surely sent her to the spleen sooner rather than later...but..

But, AE-3803 used her weaknesses to push herself forward. She strived to do better and in return, the universe treated her well in kind. She was gifted with friends from the immune system, a determination to accomplish her task that could outshine a Killer T-Cell's, and so much more.

That's probably why NT-4201 doesn't really say much when she sees her red headed mentor hang around the strange white blood cell. It's rare to see a neutrophil and an erythrocyte talk for more than a few minutes regarding their work, rarer still to see them laughing. Obviously, from her years as an erythroblast, there were no guidelines or warnings concerning affiliations such as these. Heck, if they really wanted to, they could have befriended the myeloblasts.

Yet, AE-3803, so special and so hopeless, managed to be one of those who breached the boundaries and reached out to a neutrophil.

Perhaps NT-4201 could learn from that.

After all, AE-3803 was and still is her mentor.

DB-5963 is a veteran erythrocyte. Noticeably older than the residents of this strange new body, he doesn't mind getting a tour from a rookie erythrocyte...and her neutrophil friend. Maybe it's because he's new or maybe the body is generating friendly immune cells, but wasn't their relationship unusual? Technically, he was all right with it, but whenever he sees that strange neutrophil hanging onto AE-3803's every word, there's a sense of lazy dread.

Back in his old body, the immune cells were savage beasts who lusted after the flesh of invading bacteria. They were meant to be feared and respected, not befriended. But here he was, in another body with only a handful of his original brothers and sisters, trying to reconcile the fact that maybe…

But was it really possible for an immune cell and a red blood cell to get along so well? DB-5963 can't help but think that there's a catch somewhere. Immune cells just weren't nice, just like red blood cells weren't meant to protect. There had to be something going on behind the scenes.

Yet, the more time he spent with his new red blood cell acquaintance and her neutrophil friend, he began to feel less disturbed and a little more worried. Didn't she realize that white blood cells were supposed to kill indiscriminately when ordered? What were to happen if she were have a virus or an abnormality that was deemed unsafe?

What then?

What would the both of them do?

But it's not DB-5963's place to say anything.

Instead, he joins the rest of his blood cell brethren with their deliveries.

Maybe it's all nothing.

In the end, it was up to AE-3803 to decide if her friendship with an immune cell was either malignant or benign.