The sound of a weapon firing rings throughout the room as I clench my eyes shut. Despite having thrown up a shield to protect myself and Chaser, I don't feel the drain of a round impacting with the magical barrier. That's when I feel something falling on my head, like small snowflakes which all land within my mane.

Hearing John screaming, I open my eyes to find him lifting his one hand to his head as the other arm throws the shotgun across the room. Looking overhead with a quick glance, I can see a section of wall missing as dust and debris continue to trickle onto my body. John stumbles to the side of the room as he continues to scream at the top of his lungs. Reaching a mirror, he punches the glass as he stares at his cracked reflection, "Get the fuck out of my head!"

'Get out of my head'? What does he mean- My eyes widen as I drop the barrier and quickly climb off the bed. The corruption... could it be back? But, he wasn't able to fight it off last time. How is he fighting back? John's head suddenly twists to the side as he glares towards the two of us, the sunglasses on his head preventing us from seeing the condition of his eyes.

John's hands suddenly grab onto his sword and draws it from his scabbard, "No... the bitch must die!" His voice sounds hoarse as he speaks, similar to how it did when he was corrupted and attacked us in Ponyville.

As he approaches, Chaser finally awakens from his shocked state as he watches John advance towards us. Leaping across the bed, he grabs onto the rifle which rested at the foot of the bed. With his weapon in his hooves, Chaser rolls over the bed and stands as far back from John as possible. "John! Stay back!"

To my surprise, John stops as he looks to the rifle. Seconds tick by with nobody moving, the only movement eventually coming from John as his arms seem to begin shaking by themselves. Opening his hand, the sword drops to the floor as John collapses onto his knees. Looking to Chaser, he falls forward onto his hands as he lets his head hang low, "H-help me... please."

Using my magic, I reach out to John and remove the sunglasses from his face. With nothing obscuring his eyes, he finally lifts his head as he looks towards Chaser. His eyes are neither in their normal condition or white like we had previously witnessed. His eyes appear faded, the natural blue of his eyes are no longer present as his eyes adopt a light grey, threatening to turn to the white state that has become associated with his corruption.

The doors to the bedroom suddenly burst open, dragging my attention away from John and Chaser. Entering the room is a group of five guards, alongside Shining Armor and Spitfire. The Guards all have their weapons raised as they enter the room, looking around to find the individual who discharged the weapon.

Without warning, John's hand snaps forward towards Chaser's rifle. With a hold on the rifle, he slams it back causing the stock to impact with Chaser's body. With the weapon torn from Chaser's grasp, John climbs to his feet as he turns back to me. Adjusting the rifle, a number of guards all begin to bark order for John to drop his weapon. John ignores this as his eyes seem to change before me, turning white as he seems to lose control once again.

Slowly twisting the rifle, he prepares to aim it at me as a magical field wraps around him. Following the magical energy, I find Shining Armor's horn glowing as he creates a makeshift cage to contain John. With the field fully erected, John is trapped within it as his body seems to shake once again. Tearing his eyes away from me, he slams his head forward into the field as he seems to be fighting himself for control.

When his eyes lock on me once again, the colour once again seems to be returning. Sorrow and fear begin to fill his eyes as he looks to me. Dropping the rifle, his body seems to spasm uncontrollably. Shielding his head, he twists violently as he seems to be losing control once again. "D-don't let it come back! I can't-"

John releases an ear piercing cry as he collapses back against the barrier. Within a few seconds, he's quickly back to his feet as he starts to punch the shield with all his might. With his efforts being in vain, he relaxes his stance as he glares directly at me with those lifeless eyes. He's trying to fight back, but it's clearly a losing battle for him. Despite his attempts at maintaining control, it seems that John is unable to stop it. His corrupted self remains in position as he glares at me with the intent of causing me serious harm.

The guards begin to position themselves around the barrier with their weapons raised, keeping their sights locked on John as he keeps his focus on me. As he maintains the shield, Shining steps up to me as his eyes look towards John is disbelief. "What in Tartarus is going on? Who fired?"

"It's John," Chaser states as he joins the two of us. "I... I think he's corrupted."

"Corrupted?" Spitfire asks as she cautiously treads towards us. "Corrupted how?"

I run my forehoof over my foreleg as I look back between her and Shining Armor, "During Tirek's attack in Canterlot, he remained here in Canterlot to protect the Princesses. He was influenced by Tirek, his mind manipulated to follow orders that Tirek gave him."

"But, that was months ago. That doesn't explain why he has suddenly fallen under his influence again." Spitfire sighs as she looks towards John. "Tirek is in Tartarus and without his powers. How could he have gotten access to John to influence him?"

"That doesn't matter," Shining interrupts as he steps closer to the barrier, disrupting John's line of sight to me. "The guard unit in the Starswirl the Bearded wing of the Canterlot archives were attacked earlier tonight. Valuable magical artefacts have been stolen." Shining locks eyes with John, "And I've got the feeling we have who was responsible right here."

"You'll need proof." All of our heads turn to John as he talks with a large smug on his face. "You've had it out for me for ages. You're just trying to pin the Royal Guard's incompetence on me."

The newly appointed Major tries to glare at John in an attempt to show his confidence, "The artefacts go missing at the same time that you're under the influence of another's magic. I'm pretty certain that it's safe to assume that you were responsible."

John leans forward, his forehead pressing against the barrier as the smug expression only intensifies. "So, where is your evidence? You'll need witnesses, and I imagine that all of your guards didn't see their attacker. That rules me out. Not to mention the fact that this world lacks the technology for CCTV, so they'll be no video or photographic evidence of me. You're out of luck, shit for brains. You'll never prove if I was responsible or not."

"I'd hate to admit it," Spitfire adds as she steps alongside the Major, "He is right. We have no proof. Although it seems likely that he was responsible, we have no sort of evidence to prove the theory."

John chuckles as he steps away from the shield, "Unlucky."

Shining Armor growls in frustration as he turns to the group of Guards, "Somepony get the Princesses. We need to deal with this."

Not long after returning to my tower, a set of Guards had made their entrance and had informed me of a situation in the guest wing of the castle. Apparently, the situation was now under control, but Shining Armor had requested mine and my sister's immediate attention. Quickly making my way to the wing, I find that it has been sealed off with a number of guards stationed at the doors on high alert. Not even a number of key officers who were remaining at the castle were allowed to enter.

With the guards standing to attention and opening the doors for me, I quickly make my way inside before a number of officers begin to bombard me with demands that I inform them of what's going on. Walking down the hall, I find that one room, in particular, has a large concentration of guards positioned outside, including a number of Celestia's own personal Guard.

From the doorway, the first sight that I'm met with is a large section of wall which has been damaged. The paint has been chipped away as a number of indentations cover the damaged wall, almost as though somepony had decided to take a couple of shots at it. Chaser and Sunny are both sitting alongside one another at the far end of the bed, Chaser trying his best to comfort her as he drapes his wing around her.

Moving around the door, it's quickly closed behind me as my eyes widen at the sight before me. Contained within a magical field is John, a rifle resting at his feet as he keeps his head lowered. At the sound of the door closing, his head slowly rises to allow his eyes to meet mine. I freeze at the sight before me, John's eyes clearly showing that the corruption which had previously plagued his mind has returned.

No... I-I destroyed the influence which was within his head when I entered his dreams. How has it returned so quickly? My heart sinks when a realisation hits me. If he's been influenced, then that means that it has only recently grown strong enough. I left him alone in the streets of Canterlot as he lost control of his mind. I let my emotions get the better of me and left him to fend for himself... it's my fault. He had no chance, and I left him to fight it all by himself.

Quickly attempting to hide the sorrow that's starting to show on my face, I turn my head to the Major as he stands alongside my sister and Spitfire. "What's happened?"

They don't seem to notice the worry I had as Shining Armor quickly replies. "The Captain has had his mind influenced to carry out the work of another. Artefacts from the Canterlot archives have been stolen, we believe that he is the one behind it."

"We've been over this, prick, you need evidence." John states in a hoarse voice. "You'll never pin that on me, give it up, you stupid cunt."

The irritation on Shining Armors face is clearly evident as he tries to ignore John's outburst, "He also attempted to attack Corporal Sunny Shield and Sergeant Night Chaser, hence the damage to the room."

"That's wasn't John!" Sunny quickly shouts as she jumps off the bed. "He was trying to fight back. He had the shotgun aimed directly at us but John was able to take control to save us."

My eyes briefly flick to John upon hearing the news, "He was able to fight back against the corruption?"

Sunny nods as Chaser steps alongside her, "He shouted at his own reflection. He was telling it to get out of his head... he was begging for our help."

"That man is weak!" John shouts from within the force field. "Unable to kill a simple bitch, all because of his weak emotions and morals." His head slowly turns to me as a smirk spreads across his lips, "He holds back... unlike you."

Before he can go any further, I face the force field and stomp towards him. "Captain John Davies, you will be quiet! That is an order!" He's under an obedience spell. Perhaps receiving an order from a superior will override the orders previously given to him.

He looks at me for a few seconds before laughing demonically, "Fuck off. You don't give me orders, I've already received my orders."

"From who!?" Shining shouts in an attempt at interrogating him.

"I'm not telling you crap, you pitiful piece of shit. You'll have to torture me to get so much as a single piece of useful information from these lips." His head once again shifts to me as he continues to grin. "So try and boss me around all you like, it won't do shit to me."

Closing my eyes, I channel my magic in order to cast a spell to render John unconscious. Within a few seconds, my magical energy pierces his flesh and mind as his eyes drift closed. Slumping back against the magical field, he slides down the edge before coming to a stop on the floor.

With John now unconcious, my sister steps alongside me as she looks to his sleeping form. "I don't understand. Why is his corruption now returning? We cleared the corruption which had manifested in his mind."

I release a slow sigh as I run my forehoof over my eyes, "I don't know. John called out to me in his dreams as the corruption seemed to return. I cleansed his mind, but once again it has returned. It seems that without any magical resistance, the corruption will continue to return."

"Then he cannot remain in command," Shining states as he looks to us. There is a brief silence until he continues, "He poses a significant security risk. With him in command of a military unit and being entrusted with classified information, he cannot be allowed to remain at his post. Somepony can wait for his mind to weaken then easily manipulate orders through him. He could give false orders, release military secrets, or even be used to carry out a sabotage on our own facilities. Nopony will question a Captain walking around a base, allowing him to walk around with ease. We cannot allow this to happen."

Celestia lowers her head before turning to me, "I'm afraid what the Major says is true, sister."

"Hold on!" Chaser interrupts as he looks to us in annoyance. "After all that he's done, you're just going to kick him out? You can't do that to him. Being in the Rangers is all he's got here, you can't just throw him aside after all the work he's done."

"What choice do we have?" Celestia retorts as she addresses Chaser, not seeming to be off-put by his outburst. "It is true, John has done many good things for the Guard, but his mind is no longer his own. The risk is too much. If the corruption is returning and we cannot fully purge his mind, then I see few alternatives."

I look to Celestia in disbelief, "We cannot do this to him. We must try to cleanse his mind."

"I know, I wish to help John as best as I can. But, if he cannot be cleansed of this corruption, then we must seek alternatives. And if he is to return, it may be best to give command of the Rangers to another officer under your command, Luna."

My eyes widen at the bluntness of Celestia's words. "Replace him, because of something out of his control?"

Celestia tries to give me her best reassuring look, "This is not the only reason. Sister... John has proven himself as a frontline soldier and as a sufficient trainer. I simply think that keeping him as the commanding officer of the Rangers will divert his attention. With the issues that have arisen in the south, we may need him to be focused on the task at hoof. I don't want to remove him from the guard unless it's the only option available to us. I'm only saying that perhaps command can be given to another so that John can keep his focus on his selected team and making further advancements."

I turn away in contemplation as I think it over. John did always say that he was more of a frontline soldier, not one for formalities and ceremonies. When I first gave him command he'd always try to find an excuse to engage in practical work or to carry out patrols. Perhaps I could give command to Brigadier Swift, he's seen the advantages of John's methods and would likely allow him to continue to his full potential. Looking back to my sister, I nod my head. "I'll have to discuss it with him. I can't just take it away from him. For now, we've got other priorities. We need to enter John's subconscious and clear the influence that holds him. He tried to fight back against it, we should be able to free his mind for a time in order to find a permanent solution."

"W-would it be possible?" We all turn out focus to Sunny following her question. "If his corruption returned with no magical influence... could we even cure him permanently?" None of us speaks as we're all slowly hit by the sudden realisation. After previously purging his mind on two occasions, it has returned. After the second time, it seems that his mind has been lost further as it returned within a number of days. If I can't cure him... he may be lost forever.

"My, my, such gloomy faces." Everypony in the room turns on the spot to find an often unwanted presence hovering in the air, Discord. "Normally, I'd have to engage in a little chaos to see ponies looking so... joyless."

I glare at him as his body slowly lowers to the floor. "Discord, what are you doing here?"

"Well, I heard that a little bit of fun was happening here in the castle. Now, I'm usually the first one to engage in a little mayhem, so seeing such a commotion peaked my interest."

Chaser glares at Discord, "Do you think this is funny?"

Discord chuckles as he strolls towards the magical field which still contains John. "It is quite amusing, yes. All you ponies gathered around trying to figure out whether you can save this one individual... almost as if... he's so important to you." His head slowly turns to me as a knowing smirk emerges on his face. "To answer your question... I'm here to lend my assistance."

"You? Assistance?" Chaser scoffs as he turns away. "Last time you were brought along to help us, you betrayed all of Equestria by siding with the thing that messed with John's head."

"Yes, well, I am familiar with the things that I've done. I'm the spirit of chaos, I tend to do many things at the tip of a hat." With a knock on the shield, it collapses causing John to fall back onto the floor. "The Princesses failed to clear out the little gift that Tirek left in his head. I am the one who can remove it, easy."

My eyes narrow as I pace across the room towards John's unconscious form. "And you expect us to trust you? In the head of a Captain of the Equestrian Guard."

"The corruption will keep returning and you lack the power to destroy it. I, however, have more power than both you and your sister put together." Strolling confidently towards Celestia, he turns back to me with a self-satisfied expression. "That's why you've only been able to defeat me with the elements. I can cure his mind... just say the word."

My head is violently rocked back from the impact, blood draining from my mouth as my other self-continues to assault me. With a solid punch to the gut, I fall back in the chair which I find myself tied in, impacting with the cold concrete below. Since my attempt at fighting back, my other self has ensured that I'm in no condition to fight. My eyes only have a few moments to scan my surroundings, but I find myself back in the interrogation room I spent many hours in during training, the same place the corruption brought me during my dream.

I'm able to see when he's in control of my body, he seems to stand still like a lifeless husk with his head lowered. There are times where I could hear things taking place, almost as if I was hearing what my body was. Only a few sounds came through, the sound of a spear being fired, magic taking hold of something... and the voice of my friends.

I knew what my corrupted self tried to do to Sunny and Chaser last time it was in control, I couldn't let it hurt them. I was able to break out of my restraints, attack the conscious of the corruption and keep it away for a few moments. For a few seconds, I was back in my own body but felt nothing but agony. I tried to plead for help, but the corruption soon took control by attacking me. With my body now seemingly unconscious, it has decided to take its anger out on me for ruining its revenge.

"You fucking cunt!" He screams as his foot comes down on my stomach. I splutter violently as an excruciating anguish races through my gut. "I had that bitch! She was literally in my sights and you ruined it!"

I groan as a small amount of blood fills my mouth. Coughing up a small amount of blood, I look up to my other self. "Y-You're not in control of me."

Leaning down, he lifts the chair and myself up as he laughs. "Not in control? I have your body under my control, with yourself in a position unable to fight back. I think it's safe to say that you're the one who isn't in control." A sharp pain shoots through my head as his fist comes into contact with the rear of my skull, my vision becoming temporarily blurred and distorted. "And when your little body wakes up, I'll just have to finish what I started."

I'm about to open my mouth to respond, until the sound of clapping interrupts me. "Bravo. Bravo, how marvellous." My head slowly turns to the source of the noise, my head taking a moment to allow my vision to fully return. Walking towards us is Discord as he looks at us with a wide grin. "You never cease to amaze me. Using a place from memory as your last line of defence. An interrogation room, no less. And what makes this so spectacular is that you're getting plenty use out of it, just like it was designed for."

The sound of a rifle cocking causes my eyes to peel away from the spirit of chaos. I watch as my other self steps around me, a SA80 raised towards Discord. "Big fucking mistake. You've just come into my territory... my domain!"

Pressing the butt of the rifle against his hip, he compresses the trigger as he begins to fire the magazine fully automatic towards Discord. I watch in bewilderments as Discord's body seems to shift, allowing natural holes to appear in his body in order for the bullets to pass through him. After a few seconds, the sound of the last casing hits the floor, yet Discord seems to be completely unscathed by the barrage he just faced. You can't be serious... Can't bullets kill him?

Discord finally moves as he raises his paw to catch a glass of what appears to be chocolate milk from the sky. "Did you miss me?" Bringing the glass to his lips, he throws his head back as he takes sizable gulps of the drink. My eyes widen as the liquid begins to drain from his body as he drinks it, small pin holes all over his body causing the chocolate milk to pour out of his body like a fountain. Turning his head to the corruption, a coy grin spreads over his lips, "I guess not."

"W-what?" My corrupted self asks in disbelief as he examines his rifle. "How is that possible?"

"Please, do you really think that nopony has ever tried to use a physical weapon against me? Your rifle is no harder to avoid than a simple blade, all be it much faster." Reaching his claws out to the rifle, he clenched his talons closes and drags the rifle for the corruptions hand. With the rifle hovering in front of Discord, he opens his talons once again causing the rifle to disassemble into dozens of pieces before impacting the floor.

Stepping forward, Discord presses his paw against the corruptions head as a magical aura is emitted. I watch as the corruption begins to scream in torture, his body appearing to turn to particles as his face begins to slowly break away and scatter into the air. I watch in horror as the version of myself dissolves in thin air, collapsing entirely in Discord's grip before vanishing into the air.

Retracting his paw, he tilts it to face him before blowing the last particles free. "And the Princesses found that difficult."

I stare at him in disbelief as I try to pull free from my restraints, "What did you just do?"

"Isn't it obvious, I removed the corruption from your mind." Graspinging onto the rope, Discord removes it with one pull before throwing it over his shoulder. "You, truely are an intriguing creature. No magical resistance, yet you were able to try and fight it off. I suppose that may just be the human spirit, or a sign."

I lift my hands and rub them cautiously over my marked wrists, "A sign about what?"

"That you're capable to control it."

"Control what? The corruption?"

"Ding ding! Somepony give the Captain a gold star!" Discord exclaims as he throws his arms out, a golden sticker of a star materialising on my chest. "It's only corruption when somepony else manipulates it. But if you were the one in control, then it could aid you."

I cock a brow as I stand, my legs buckling slightly as pain courses through my body. "Aid me? It does nothing but make me lose control. How could that help me?"

"The human species is quite an interesting one. I must admit, I am a huge fan of the chaos I've seen your species cause in your little head. Global conflicts, civil wars, man-made disasters and so much more. But, for all your technology and tendency towards chaos, there is one thing that you humans lack. Magic. Without magic, you humans are weak."

I scoff as I step over the disassembled remains of the rifle, "Weak? How does that make us weak?"

"Ha, please, how doesn't it make you weak? A filly with a simple spell could have the potential to stop you if she used it correctly. You humans have no protection, and that certainly has been proven with the corruption repeatedly taking hold of your mind." Looking at me with a confident smirk, the spirit of chaos begins to pace around me. "I must admit, I've taken quite the liking to you. You've made Equestria fun, I don't even need to do anything for the entertainment to commence. For that, I shall give you a choice."

As soon as those words leave his mouth, a sickening feeling begins to fill my gut. "What choice?"

"You have two options. One, I cure the corruption and remove it entirely. This would leave you completely cured, but you could easily become influenced once again if somepony uses a similar spell on you. You'd be back to your old self... but that isn't quite as fun. I will cure your corruption but you will owe me three favours, all of which will be decided when I feel the time is right."

I lower my head as I think the option through. Cured of the corruption and back to my old self. It would allow the others to regain their trust in me, knowing that I'm no longer influenced by Tireks magic. However, owing the god of chaos three favours doesn't sound very appealing. It feels as though I'm practically making a deal with the devil.

"Or, there's option two," Discord continues as he looks at me in an attempt to gauge my reaction. "I shall keep the corruption tucked away deep within your head, hidden entirely by the deepest magical scans." I'm about to protest before Discord clicks his talons forcing my mouth shut. "However, it will only take orders from you. You will maintain control and nopony else can manipulate it unless you allow them to. Think about it, the increased strength and power at your disposal."

Inaudible mumbles come from my mouth as I attempt to speak yet find myself unable to open my mouth. Clicking once again, I'm able to open my mouth. "What do you mean 'increased strength'?"

"Surely you must have noticed the increase in physical strength while it is in control. When you first arrived, a kick to the chest broke your ribs and knocked you out. While under the influence of the spell, you've been able to withstand the same injury and much more. You've been shot, assaulted and able to fight off more than one opponent at once. It not only increases your strength but also your reflexes and agility... making you a far superior soldier. With that at your disposal, you could call on it to help you out of a... sticky situation. And, as a nice little bonus, with the influence still within your mind, you'll be invulnerable from other spells which would influence your mind to gain control. The only way they'll see the corruption is when your eyes change along with your voice, so you'll just have to keep that hidden while you're channeling it."

Increased strength and agility, it would make me capable of fighting out of tough situations. Also, having protection from spells which could break my mind would make up for my lack of magical resistance. But if the others were to somehow learn that I still had the corruption within me, they would likely disapprove. They'd think that I'd be unable to control it, likely to turn and attack them once again.

"Well, Captain?" Discord asks as he chuckles. "Which will it be?"

I shake my head as I let out a sigh, "Why are you doing this?"

"Honestly?" Discord shrugs as his grin intensifies, "I'm bored. This seems like a good bit of fun. You're far more entertaining than most of the ponies I know. I want to keep it that way. Now, make your choice. But be warned, both will have advantages... and consequences."

"And if I refuse to choose?"

"Then I let the corruption return as normal. I'll tell the Princesses a sob story about how I'm unable to cure you." Discord laughs again as he jumps onto the chair as leans back in it. "Tick-tock... You don't have all day. And, just to be nice, I'll throw in an extra surprise when you make a decision. Something which will allow you to create a bit more carnage and chaos on the battlefield."

A cure for the corruption, but I owe him three favours and am able to be influenced again by someone's magic... Or control over it, giving me an edge when it is really needed and protection from further corruption, but could lose everyone's trust should they learn about it...

What do I choose?

Author's Notes:

It's time for a vote!

A total cure which leaves him vulnerable once again and owing Discord three favours...

Or control of the corruption, giving him more power and protecting him from manipulation, but at the risk of others learning of the corruption within him...

Both decisions will have an impact on the story, for better and for worse... so choose wisely.

(Updated 19/09/17 - 08:30 BST) Voting for this chapter has now closed. Thanks to all who voted. There may be future instances where you can vote again within the story to choose what happens