I should note I'm being vague about exact anatomy here not out of a lack of knowledge on turtle anatomy (I actually took my class on it just a year ago in vet school lol) but because I'm not sure how exactly the skulls of *mutant* turtles translate so I'm going half-human half-turtle on this as much as I vaguely can.

Special thanks to BlueBlingThing and Tazzy for the feedback and support on , AO3, and tumblr!

TMNT, Leonardo, Raphael, Michelangelo, Donatello, Splinter, and LeatherHead © Mirage Studios
story © Turtlefreak121

Flicker
Chapter Thirteen: Fleeting Memory

He woke up happy, and that was enough to tell Don that the foggy dreamlike walk he had been taking for ages was beginning to end.

For so long he could hardly put it into terms, Don had woken up not to a particular emotion but to a slate blankness that improved (or, sometimes, theworst times, digressed) from that point on.

The emotionlessness, the confusion, the droll gray that he had been living had been going on long enough that even in his most confused states, Don knew it was supposed to be normal.

Happiness, excitement, was not normal anymore.

But Don held hope that it soon would be.

He sat up in his bed, ram rod straight, and put a hand to his chin.

Good news. He recently had had good news and that was why he was in such a positive state for once.

Having that happiness gave him enough hope and determination that he began racking his fuzzy, confusion idled brain for any reason at all that he might have felt the way he did.

If he remembered it, he could find a way to hold onto it, he was certain of it.

The effort at first seemed to be getting him nowhere, trading that fleeting pleasure with a tinge of aggravation and regret.

Instead of caving to such things, however, Don looked around the room for some sort of sign, some sort of clue as to what he had been so damn happy about when his eyes locked on the door.

It was only a flash of memory, of Leonardo and of the whole day before him that had happened and–

There was something wrong with him, Don realized. But not terrible – no, at least, it wasn't terrible that he knew something was wrong, something was causing him to be the way he was, to think with such a hazy fog and to not remember or be able to process what was around him.

Not wanting to lose his progress, Don kicked off his sheets and made a beeline to his desk.

There were probably more delicate and calm ways he could have looked for a pen and paper, but in the heat of the moment Don lost all sensible manners and quickly threw aside half the contents of his desk.

He grabbed a pen and then reached for printer paper only to freeze and see with some joyous surprise that he had an entire pad of unused sticky notes by his computer mouse.

"Perfect!" he said contently.

Grabbing the pad and his pen, Don sat on the floor, ignoring his mess, and feverishly began writing everything he could remember about the day before.

There was Leo. And LeatherHead. The tests. His breakfast. The strange flashes of light. The diagnosis. The treatment.

Don's chest swelled with pride as he sat back and looked at the sticky notes lined up before him.

It had been so long since he felt so focused, so honed. And he couldn't help but wonder how long it had been since he had felt that good about much of anything.

Of course, there was also the question of why he hadn't thought to write things down before. The sort of thought that simply didn't sit right with him as it was brought to his attention.

Before it could bother him too much, however, there was a knock at his door and he quickly looked to see that it was once again Leonardo who was standing there.

There was an uneasy look on Leo's face and he seemed reluctant to even be in the room at all. But his eyes were shifting heavily back and forth from Don to the mess just beside the computer desk.

"Uh, Don?" Leo asked, looking back with the concern still heavily in his gaze. "Is… Are you alright?"

Don smiled genuinely toward his brother and held up some of his sticky notes, the ones that went through all of his conversations with Leonardo and LeatherHead to the best of his memory. He watched as realization lit up Leo's face when he read over them.

"More than alright," he said to Leo. "Now let's get going to LH's. I'm ready."

Leo let out a relieved laugh. "I'm glad to hear it, Don. More glad than you even know."

Gathering up the sticky notepads, Don shoved them into his duffle bag and then slung it around his shoulders. He knew there was a very high chance that if he got off task, things would start to fall apart again, but Don was nothing if not determined.

It was all going to work out, he had to be sure of it.

Sometimes even Leonardo wasn't entirely sure how he managed to be the one to keep things together.

The words flying back and forth between April and LeatherHead made little sense to him, but he listened and attempted to absorb each and every one of them. A task only made more difficult by the insistence Don had in sharing every other sticky note he wrote on so that the eldest turtle could find somewhere new to add it to the tables and equipment around them.

Donatello's newfound enthusiasm for memory and for the steps he took into preserving it was a welcomed change of pace, but Leo had little time to humor it when April and LeatherHead seemed intent on bringing up drastic measures.

"This CT compared even to yesterday's is showing progressive change. It's only going to get bigger," April said, downing what had to have been her third coffee since Leonardo's arrival.

Which was staggering considering that, according to Casey, they had been at LeatherHead's since Mikey and Raphael had stopped by the apartment the night before.

Leo frowned at the statement and moved his hands over the table's ample number of printed scans. They had been running tests with painstaking attention to detail since before when it was just Leo and LeatherHead. And the information and seemingly miniscule changes had led to things rapidly becoming more complex than Leo's timid understanding of medicine and anatomy.

When Don handed him three more sticky notes, Leo barely glanced over them before finding another spot for them on the leg of the table.

Donny was on his second pad of notes since they arrived and begun performing tests again.

"The progressive changes are precisely why I am concerned with any course of action, Miss O'Neil," LeatherHead said with concern etched deeply into his brow. "Such large changes on such a short time table will make it difficult for us to make a course of action that will still be relevant after the time it would take us to decide what choices to make next. We must inhibit growth first."

Leo looked for the mass on the scans they had pointed out to him before. An obstruction – a invasive growth in a delicate area underneath the brain. To Leo's untrained eye it seemed so small, so almost unnoticeable, that he had to glance at the practice scans that LeatherHead had performed on him the day before as a sort of control sample to even really notice.

But, given how April and LeatherHead talked about the tumor, it was large enough to be a true problem.

"It's going to continue being dangerous to Don's health so long as it's there, right?" Leo asked, glancing up to his friends as he did so. "Until we get rid of it, it's risking killing him."

Both April and LeatherHead glanced to each other before fully turning toward Leo.

Crossing her arms, April nodded. "Yes. Where the tumor is is precarious – it's not only affecting Don's hormones which is a big cause of the mood swings and changes he's been having as well as how the rest of his brain is functioning, it's close to a bundle of nerves which receive signals from his eyes. It's making him experience illusions and depreciated light reception. If it's not removed, those things can only get worse."

LeatherHead shook his head, a grimace on his face. "However the procedure would require us to have equipment in order to operate through the sphenoidal sinus, and to keep visual so that we may not only remove the obstruction butalso keep clear of the carotid arteries which supply blood to his brain. Hitting those will have disastrous outcomes."

"It requires a nanite camera – which we have built before," April argued already. "And if we put off the surgery a few hours, you and I can practice with the equipment for the surgery a few times on models."

"I must build the equipment, Miss O'Neil, and it was Donatello's specialties for nanite technology before which he has far more experience in than either of us," LeatherHead sighed heavily. "I am uncomfortable with speaking in terms of hours, we need patience. Which we can only afford by inhibiting grown first. Perhaps some of the studies we read on matrix metalloproteinases–"

April took her turn shaking her head. "You think there's not time to waste onpractice but that there's time to track down and – what? – steal rare pharmaceuticals?" she demanded.

Leonardo stepped forward, grabbing the scientists' attention again. "What is the safest option for Don?" he asked. "I want us to do whatever that option is, alright?"

The two looked ready to debate the new angle when there was an unexpected voice clearing behind them.

They all turned and looked at Don who was holding up sticky notes and wearing a very, very exhausted smile.

"I think, maybe, I should be the one getting a say in this, guys? Just a bit?" he pointed out, stepping forward and peeling the sticky notes he stuck to his arms off one by one. "I'm feeling better today, but I know the only reason for that is because I'm… focused. Because I have an answer and as long as that's front and center I've been able to write down everything else. Everything I'm scared of forgetting." His eyes flickered up to them. "But I still see things blurry. And there's a song I can just about hum that keeps playing in my head even though I'm pretty sure it's not really there. And I can't write everything down because… I don't know what's important until it's gone. Like breakfast this morning. No idea. Did I even eat breakfast?"

When Leo realized his brother was looking to him for an answer, he swallowed down a breath he didn't realize he was holding and nod. "Yeah. Toast."

Don's smile grew brittle. "Yeah. I don't even know if I remember what toast tastes like," he said with a striking honesty that felt painful to Leo. He then glanced to April and LeatherHead. "It might be risky, but we've gotta operate. Because it's worth the risk to me. And I should be the factor that matters right now, right? I should get to decide if I remember toast or not. So… how about it? Before I forget this conversation happened can you give me your word that you'll try to remove this thing? That we'll do it as soon as possible and not waste time on inhibitors and drugs and things we can't possibly get a regular supply of anyway?"

They looked at Don and Leo felt his breath taken away all over again.

It was him. It was his brother, right there in front of him again. At least, however much he could afford to be right then.

Leo swallowed and nodded. "Absolutely, Don," he promised. "You're the deciding factor."

April and LeatherHead looked to each other.

"We can start reading up on the procedure now, I'll read out loud while you construct the equipment and think of some creative things with that Utrom-taught genius brain of yours," April offered, grabbing a nearby medical textbook.

"And I shall ask the turtles to call the Justice Force on my behalf and ask of advice from their nanite expert who corresponded with Donatello," LeatherHead nodded. "The more influential technology across species the better."

It all sounded like a plan, but Leonardo still felt fear gripping him.

He watched as Don walked back to the desk and began reading over the various notes with no look of familiarity on his face.