Disclaimer: recognised characters owned by Hasbro/TakaraTomy.

Morborum

"How long have you been noticing these lapses?"

"For a while. Since before we came to Earth."

Ratchet paused in his questions to subject his patient to a stern glare. "You, of all mechs, should know better than that. Did you not think to tell anyone?"

"I have mentioned it to Percepetor. I have given him a sample of lubricating fluids from my meta-processor receptacles. He required it for analysis."

"And have you heard back from him?"

"Negative."

The medic turned his head away pensively, a small thoughtful sigh escaping his vents. "Yet you did not come to see me sooner. I am surprised at you."

A shrug. "I had not thought such a trifling glitch necessary to cause fuss over. It has merely become a liability."

"And yet you dictate protocol to all warriors that, should they feel in the least abnormal, they should come to me or First Aid at the first possible opportunity. I had not taken you for a hypocrite, Prowl."

The tactician shrugged his monochrome shoulders. "I did not come here for you to repeat my protocol to me," he stated, quite calm, "I came for a full diagnostic. You have a function, please stick to it."

Ratchet did not respond to his superior's curt and often quite hurtfully blunt way of stating facts, instead concentrating on running the diagnostic requested of him. Eventually, his need for information pressed him to resume his questioning. "These lapses, do they vary in intensity?"

"Often," came Prowl's monotone response, "sometimes it is merely a glitch in my vocaliser, once I was disabled halfway through a skirmish with pain despite not having sustained any injuries. I can only assume the cause to be the same glitch, and, if I am to retain efficiency, I need it removed."

The ambulance-transformer nodded once in affirmation. "I shall do my best. I have already sent a radio signal to Perceptor asking him to deliver any results he may have obtained from the CNA sample you gave to him. Micrometallurgy is his strongest field; I have every faith in him."

Prowl sat back. His door-wings twitched as they brushed against the wall. "It will not be too long, I hope."

"Shouldn't be."

Placing the notes he had scribbled on the surgery bench, Ratchet began a complex series of charts and theories and analyses in a shorthand that Prowl could make no sense of, his azure optics flickering and glimmering in a mixture of puzzlement, contemplation and concentration. The white mech barely glanced up when Perceptor let himself in to the medical bay to place a datapad of his own findings on the bench, excusing himself with a small word whispered in Ratchet's audio and a kindly nod to Prowl, which the sub-commander did not return.

Eventually, Ratchet glanced over Perceptor's data gleaned from the samples Prowl had given the scientist, his brow furrowing. Prowl watched impassively, neither drawing his own conclusions nor worrying whether or not this boded well for his health.

The pains had been becoming more frequent these past few deca-cycles. Since onlining on Earth after thousands of vorns in suspended animation, he had thought at first it was his pistons realigning after the extended period of inactivity, but this belief of his had dissipated when he realised that all other of the Ark's warriors who suffered that sort of problem had conquered theirs within the first few orns. Prowl's pains were continuous.

Not only were they ongoing, but also unpredictable. One of the incidents he had described to Ratchet had been during a skirmish with Decepticon aerial forces. Having had a systems check-up not six joors prior and having sustained no injuries in the gunfire, Prowl's body had had no reason to go into system failure and leave him collapsed and disabled upon the floor, panting for air in his vents while pain assaulted his processors – but that had been the outcome nonetheless. He was lucky, in retrospect, that he had not been killed by the enemy in his weakened state.

Finally, after vorns of suffering lancing pains in his extremities and when he transformed, Prowl was seeing a doctor, finally he would have this glitch ironed out of his systems for good.

Ratchet leaned forwards over his datapad with a heavy frown. The tactician watched him with a curious air.

"Well?"

"... I am afraid I do not like these results."

The Datsun considered this briefly and nodded. "Whether or not you tell me, I will still have the malfunction. I only require two facts: an overview of the glitch and how long it will take you to cure."

"It seems," Ratchet said, voice soft as he studied Perceptor's notes yet again, as though determined to find a mistake in there – though sadly there was none, the microscope's work immaculate, "this glitch in question is more accurately described as a disease."

"Disease?" Prowl spat the word, "we are technological life-forms. We are not affected by disease."

"This is true, but there are some conditions able to affect Transformer biosystems that are serious enough in nature and difficult enough to cure that they can be labelled as 'disease', though it's very rare to encounter such illnesses. I believe Cosmic Rust is the only one that has been named so far, and that is only because of the pandemic."

"So what is this 'disease' that I have?"

Ratchet's expression darkened. "I suppose... it would be easiest to describe it like a branch of Cosmic Rust that attacks your internals. So... rather than your exostructure crumbling, your internal processes are slowly ceasing to function."

Prowl's expression did not change.

"Once a function in your limb ceases for a long enough period of time," continued the ambulance, "your meta-processors classify it as dead, and energon supplies are cut to that region, which is why your limbs have been growing more sluggish. Judging from what you have told me about the way this has spread, it seems to attack the vital neural circuitry connecting the motor-functions to your cerebro-circuits."

"This means?"

"Your energon pump and your meta-processors are both swathed in these neuronal capillary wires, and your spark chamber relies on them to stay functional. If this disease reaches any of these, you will die."

A very long silence. Prowl's expression still did not flicker.

"No cure?"

"Perceptor battled the Cosmic Rust outbreak with chorostop, and we do have some left. I am... reluctant to operate on a any of your vital organs in case they interpret chorostop as malignant and end up hurting you further, and coating the already-infected wires will take stellar cycles."

A single nod. "And there is no chance you could remove the limbs that have ceased functioning and replace them? If the infected circuits can be isolated from my vital components, there should surely be no risk of my termination?"

If possible, Ratchet's expression darkened further as he bowed his head forward. "Perceptor's research... I hoped he was mistaken, but he is as accurate as ever. His findings show that this malfunction has its cores in your CNA rather than the circuitry."

"This means?"

"Even if I do replace your bad limbs, as soon as the new parts are wired up to your body, they will adopt your CNA and thus the disease as well."

The Datsun nodded again, his door-wings brushing the wall as he leaned back slightly. "So there is no cure."

"... it seems that is the case," admitted the doctor quietly, "I am sorry."

Prowl's expression did not change as he stared ahead thoughtfully, his head tilted ever-so-slightly to the side, his optics narrowed and dimmed to near-blackness. "How long do you think I have remaining?"

"It is hard to tell..." whispered Ratchet, "it seems to flare up – it could be anywhere from two stellar cycles to several vorns, Decepticon attacks notwithstanding."

"I... see."

"If you wish, I could carry out surgery to replace the limbs that have been most affected. It may slow down the degenerative process while the new parts acclimatise to your systems."

But Prowl shook his head curtly. "I see no point. If my death is certain in a short time anyway then there is no point in wasting parts to perpetuate a crippled body. Rather that you give your surgical talents to mechs who actually require it."

Ratchet nodded, seeing the sense in this argument though frustrated at his own inability to do anything to cure this glitch. His optics did not meet Prowl's as he gathered his notes neatly with Perceptor's. "Do you want to tell Prime, or shall I?"

"I am able," said Prowl calmly, rising to his feet. "I am not weak-willed, I am capable of explaining my own problems. I would prefer it if this were to be kept confidential, Ratchet."

"Understood. Without your permission, no one shall know."

"... thank you for your hard work. Excuse me, I have no more time to sit and talk." The Datsun's door-wings lightly scratched the frame as he left the surgery with his head held high and his usual, unreadable expression firmly imprinted upon his pale face plates.

Ratchet watched him leave.