Author's note: I cannot apologise enough for the lateness of this update, you can blame my uni for the massive workload I subjected to. Hope this is worth the wait.

The Darkheart

[Flashback]

The great space station trembled as its entire structure buckled inwards ever so slowly. Pipes pumping oil from the bowels of the station burst open, their contents igniting and creating violent explosions; not that anyone could see or hear them. Before the sound of the explosion, or the flash of the fire could reach any of the crew frantically trying to bring things under control it was sucked into the rapidly growing singularity right in the heart of the ship; only those being caught up in them were truly aware of their occurrence.

Sprinting along one of the walkways that surrounded the black hole, one of the few to be out of range of its inescapable pull (for now at least), were a man and a woman, dressed inappropriately for the setting. The man had long blonde hair that was singed and matted with blood, dressed in a once smart dinner suit; now dirty and torn. The woman had short brown hair and was dressed in a skirt suit, similarly battered. They skidded to a halt as they reached what should have been stairs up to the next level, only for them to collapse as they reached them.

"Fuck!" The woman swore.

"No more of that," the man shouted. "You're not a human so stop pretending to be one."

"Some of their words are so good though, Theta," she replied. "Perfectly sums up the situation."

"You do know of course that the word you use actually means-"

"I can use it however I fucking like," she retorted.

Theta Sigma grimaced and spied a look down at the gaping maw of the black hole. "I really can't do with any reminders of humans right now, Dominica," he said. "Stupid apes."

"They may be stupid," Dominica replied, "but they get to enjoy much fuller lives than we ever did back on Gallifrey."

He grunted in agreement, peering upwards in search of an escape route, their own race were one of the cleverest races in the universe, ancient and wise with a vast array of traditions and ceremonies. Yet with all these traditions put in place there was little room for any one person to really express themselves, everyone was expected to toe the line, and woe betide anyone who didn't. Meanwhile the humans that he and Dominica had encountered had been free to be whoever they wanted to truly be, with very few constraints. He could see why she had become so fascinated with them.

"Only they could think that trying to harness the power of a black hole was a good idea," he said. Before she could reply he had leaped up and grabbed hold of the level above. He hung there for several seconds before straining with his upper body to pull himself up. Before he could reach one of the bars of the railing he slumped down again, kicking his legs futilely.

"You could help," he called down to his friend who was giggling like a child. She quickly composed herself and went over to give him a leg up.

With their combined strength Theta was soon able to reach high enough on the railing to pull himself over on his own. He turned back and reached down towards her, offering his hand.

Before she could reach up the floor she was stood on creaked heavily, then started to buckle. The black hole had caught up.

"Dominica!" Theta shouted in horror.

The sudden tremour had made her lose her footing, she struggled to her feet and the whole platform buckled and slowly started to tilt towards the gaping maw of the black hole, slowly tipping her back towards the edge. In the nick of time she had recovered enough to make a leap of faith. The platform was wrenched away from its supports and sucked into the abyss. Dominica hung in the air for a moment, catching hold of Theta's hand just before gravity resumed its hold on her.

"Whoa," Dominica gasped. "That was close." He simply stared back, horror at what he had almost witnessed still etched on his face. "Good thing I'm a feather weight, eh?"

Using both hands Theta pulled with all his might until she was able to grab hold of the railing herself; even at this point he kept hold of one of her hands.

"I'm fine," she insisted. "You can let go."

"I don't know what I would have done had I lost you," he said breathlessly.

"You would have had to learn how to fly the Time Capsule all on your own," she replied cheekily, climbing higher.

"I'm serious," he insisted. "I can't lose you Dom, I love you."

She froze in shock, Theta also froze surprised by his own words. He looked away out of embarrassment.

"What?" She asked softly.

"I love you," he repeated, a grin slowly spreading across his face. "I love you. I'm sorry I've been so grumpy, and I should never have given Oslo away. Things will be different now. We'll return to Earth and find him and then we can settle down, stop all this running, and be a family."

Dominica remained motionless a grin slowly spreading across her face. "Theta I-" a sound like air being blown across the top of a bottle, only sharper and more sudden, burst across the scene. Dominica's grin turned into a gasp of shock as a white flash exploded across her side. The life drained out of her eyes almost instantly and her grip on the railing disappeared along with it.

Theta lunged forwards frantically, succeeding in brushing the edge of her hands but otherwise was completely helpless to watch as the body of his lover, so full of life seconds earlier, slowly floated away from him and into the widening mouth of the black hole. He made not a sound, he was aware of nothing but the slow, and getting slower, beating of his hearts. Suddenly he couldn't breath, great gasping breaths escaped from mouth, each failing to soothe the burning he was feeling in his chest. Weakly he leant against the railing, his eyes still trained unblinking on the falling corpse. His vision blurred and his eyes began to sting, he knew he should turn to leave, but he couldn't bring himself to, it was just so painful.

Then things got worse as he became aware of a tapping on the railing. A spookily familiar tapping, one that he had heard every day during his time at the academy; a continuous four beat rhythm. Ever so slowly he twisted his head towards the sound, dread filling his heart. Stood a few metres down the walkway was a man, roughly his age, with short black hair; one hand casually tapping the rhythm, the other training a staser on Theta.

"Koschei?" Theta gasped.

"Hello Theta," Koschei replied coldly.

Theta slowly got to his feet his face a mixture of confusion and despair, his eyes unblinkingly fixed on his childhood friend. Koschei, heir of house Oakdown, a brother in all but blood, supporter of many a wacky scheme, happy to defend Theta even when doing so would put himself into as much trouble; and yet he was the one holding the smoking staser that had just killed his lover.

"I don't-" Theta began but was quickly cut off by Koschei.

"You've caused a lot of trouble back on Gallifrey."

"I know that," Theta replied.

"They are very cross with you," the man dressed all in black said loudly, making it very clear he did not want anymore interruptions. "A couple of students, including the heir of house Lungbarrow no less, hijacking an old Time Capsule."

"It was hardly hijack."

"You know what you problem always was, Theta," Koschei shouted, the staser shaking violently in his hand. "You never knew when to shut up. You have no idea the trouble you have caused."

"I do actually," Theta said gravely. One of the first things he and Dominica had done was set up a link to Gallifrey so that they would be able to keep track of goings on back home; more out of boredom than an actual interest. They had quickly turned it off after discovering the scandal it had caused, and the shame he had burdened on his mother.

"Then you'll be aware of all the young ones who have chosen to follow your example," Koschei challenged. "Magnus, Mortimus..."

"Mortimus?!" Theta exclaimed. "Really?"

"Their both flying around out there right now," Koschei nodded, "thanks to you."

"Well good for them!" Theta bit back, anger now replacing his confusion. "They're wasted on Gallifrey! They would have just become stagnant, fat old men, bored witless by the lack of challenge. And since when did you care, what are you even doing here?"

"You're saying that Magnus running about the universe alone is a good thing?" Koschei challenged. Theta froze upon hearing this. "Mortimus isn't with him, they left separately. Rallon and Millennia however did go together, not that it did them any good."

"What?"

"Dead," Koschei said coldly, "along with many others who were unprepared for what lay beyond the transduction barrier."

"And you're blaming me for this!" Theta exclaimed, the already pent up emotions blocking any reaction to news of his friends' deaths, he would have time to mourn them later. "If I remember rightly, you wanted to leave Gallifrey as much as me, if not more so."

"Then why did you abandon me!" Koschei roared. "We were like brothers, you and I, we were going to see the universe together. One look into those pretty brown eyes and all that was forgotten."

Theta stared down into the heart of the black hole, anguish filling his hearts again, a single tear rolled down his cheek. "So what is this?" He croaked. "Revenge?"

"Exactly!" Koschei spat. "It was my darkest hour, pressured by my father, scandals rocking our household, I needed my friend, but you weren't there. Where were you Theta Sigma?"

"Your father was furious with me, I thought it would be best if you were left alone," Theta justified. "I would just have been a distraction."

"He turned his fury on me!" Koschei roared. "I was bearing the brunt for your mistake and you were busy having fun with your little whore."

Theta was speechless. He had known that Koschei had been troubled when he had left, but he had genuinely believed that his presence would only make it worse, especially considering how much he had contributed to the problem. "I am so sorry, I had no idea." He took a step towards his black clad friend only to jump back as Koschei fired the staser again hitting the floor between his feet.

"Not another step," he snarled. His other hand continued to tap the four beat rhythm, only now he did it far faster and with a greater force behind each tap.

Theta was familiar with this tapping, Koschei had often done it with the end of a pencil on a desk, he had attributed it to a subconscious reaction to deep thought processes; much like how he occasionally hummed when deep in concentration. But in seeing it now, he realised that it was so much more than that. In another circumstance he may have been sympathetic and offer to help now, but an image of Dominica suddenly stiffening under the staser bolt sent brought the anger rushing back.

"So our friendship meant nothing did it?" He challenged. "Thought Vansell had the right idea?"

"Do not compare me to that snake," Koschei growled. "You are the one who has proven how little you cared for our friendship."

"I didn't murder anybody," Theta snarled.

"I'll have you know, I have every political sanction to allow me to do that," Koschei leered evily.

"Gallifrey sent you?" Theta breathed.

"They want to prosecute you themselves in a public trial, deter any young Time Lords thinking of following your example," he paused to grin sadistically. "But I don't think they will be too disappointed should you be killed instead."

"I think you underestimate them," Theta cautioned him.

"Whether you are saying that to save your own skin or because you genuinely believe it does not matter," Koschei shrugged and turned towards the balcony. "They will not reprimand me, they will be too busy falling at my feet."

With Koschei distracted Theta dared to take a few steps forwards, he managed to get within two metres before the pistol was raised nonchalantly to halt him. "I have to admire the humans," he said casually, "only they would be stupid enough to think that they can harness the power of a black hole."

Theta chanced another step forwards and found that despite his threatening with the staser Koschei's attention was solely fixed on the black hole. Catching the manic glint in his eye, coupled with the ever present tapping of his nail on the barrier, Theta realised his friend's intentions; he had gone completely mad. Looking at Koschei now he wondered how he had missed it, he must have been going mad for years. His head twisted towards Theta now grinning manically.

"Who would have thought that their short-sightedness would have gifted me the perfect tool to overthrow the Time Lords," he drawled. "With the Darkheart in my control nothing shall stop me. I shall be, the Master of the Universe!" He paused to mull over what he had just said. "The Master," he repeated huskily. "Ooh, I do like that."

"You are sounding like Magnus," Theta noted.

Koschei's attention flipped back to Theta intently. "And what is wrong with that?" He demanded. "I tried following your footsteps, being nice to people and helping others, but that was never satisfying, never got me anywhere. Perhaps the Chief had it all right all along."

Before he could say anything the platform they were stood on jerked violently knocking them both off balance. Theta recovered first, tackling Koschei in the chest. He tried to swing the staser round on him but Theta quickly blocked with his wrist, following through with a punch in the jaw. As Koschei fell backwards from the force of the blow he made sure to kick the weapon from his grip before jumping over him.

The Time Capsule was just at the end of the walkway, he needed to reach it before the pull of the Darkheart completely destroyed the walkway he and Koschei were on. Self preservation was not the first thing on Koschei's mind, however. He looped his arms around Theta's leg causing him to trip, he then jumped up and turned him onto his back, finally proceeding to rain punches down on his former friend.

The ferocity of the blows held Theta at bay for a while, but they were also manic, blinded by hatred and he soon spotted a gap. A swift uppercut to the jaw sent Koschei recoiling backwards and allowed him to regain his footing. Koschei charged with a roar, but Theta was able repel him again; this time a kick in the gut knocked the dark haired man onto the railing.

At that moment the walkway jerked again and tilted dangerously towards the centre. Koschei's eyes widened as he flapped his arms but was unable to stop himself from toppling over the side, catching hold of the railing just in time to save himself. Theta himself stumbled under the sudden tilt but was able to recover to quickly scramble onto a more stable platform.

"Theta!"

He paused and glanced back at his friend, only now seeing the peril he was in. The metal platform was twisted out of recognition, hanging from the main structure by a couple of bolts that could fail at any moment. Koschei was hanging on for dear life, eyes wide and legs flailing wildly. Their eyes met and Theta suddenly recognised his old friend, the terrified child that he had, once upon a time, stumbled across crying in a hidden corner of one of the many gardens on Gallifrey. But for some reason he didn't care.

"I'm sorry!" Koschei pleaded. "It's the drums! I didn't plan on killing her, I swear! I just saw you two together and... it just happens! It's like an animal, I have to feed it."

"Drums?" Theta mused. "You mean that tapping?"

"Only in the lightest moments, when they've been fed. More like a thumping, like a hammer," his gaze travelled across the twisted walkway as it creaked loudly. "Hurry! It won't last much longer!"

For a moment the Doctor considered his options. Koschei did seem truly repentant, he could reach out for him, take him into the capsule, and help him to recover, help him to beat those drums that he spoke of; become his doctor. He almost took a step forwards when the image of Dominica slowly floating away from him flew into his mind. And in that instant his hearts hardened.

"What are you waiting for!" Koschei shouted. "I'm your friend, we've always stood by each other!"

"That's the problem," Theta said coldly. "Koschei of house Oakdown was my friend. But you... whoever you are, are not Koschei of house Oakdown. You are not my friend."

He barely registered the look of horror on Koschei's face as he turned on his heels and strode along the shuddering platform towards the time capsule at the end.

"No, Theta please, I wasn't thinking! We all make mistakes," Koschei pleaded. "I forgive you, Theta, please forgive me. I don't want to die Theta."

"Theta Sigma is dead too," Theta threw back without even looking back. That had been his nickname, what he had called himself as a student, alluding to the lack of care he took with his studies. But he was no longer a student, he was a man grown with the whole universe in front of him. It was time to grow up.

With a sound of shearing metal the platform finally fell away, Koschei screaming uncontrollably as he was pulled with it. Even now Theta did not look back, unrelentingly striding to the time capsule. He was inches from the door when a psychic probe pierced his mind, making him freeze in place. It was a single word in high Gallifreyan, his true name. He whirled round to catch a glimpse of Koschei clawing at the air as he plummeted towards black hole, and in that moment the heir house Lungbarrow truly realised what he had just done, and it chilled him to his core.

That should have been the end of Koschei Oakdown, not even a Time Lord can survive a black hole; but the Time Lords were not willing to allow one of their most valuable asset to disappear just like that. As soon as they learnt what had befallen on the Darkheart station they sent a retrieval team, rescuing Koschei from the singularity just seconds before his final regeneration could also be destroyed.

As they nursed him back to health on Shada, it was quickly realised that Koschei had changed considerably; even when considering the numerous regenerations he had undergone in order to survive. Insanity had completely taken over the young Time Lord, who now insisted on calling himself the Master, and the temporary imprisonment had to be extended indefinitely. The Psychologist and his team still visited in the vain hope that they could restore the once brilliant mind, their mistake was that they forgot just how clever he was and mistook his insanity for brain damage.

The Master was every bit as brilliant as young Koschei had been and he did not appreciate his imprisonment in the slightest. Over the decades he analysed the workings of the prison planet and determined that it was indeed impossible to escape from, unless you had help from the outside, and it just so happened that he was the only inmate to receive regular visitors.

There have been very few accounts of prisoners escaping from Shada, but the Master is the only one to have broken out on his own, taking advantage of the regular visits from the Psychologist to engineer this success. After killing the Psychologist and using his security clearance to access the Time Lord records he began his search for the one thing that had kept him going throughout his imprisonment: Theta Sigma.

After learning that Theta Sigma, now in his third life and calling himself the Doctor, had been captured and exiled to Earth he reacquired the Time Capsule, now widely referred to as TARDISes, that he had been given on his initial mission to apprehend the Doctorand took chase. Only after several months on Earth, slowly studying the Doctor's movements and building up a powerbase of his own, did the Master act, and the Doctor was finally informed of the true fate of Koschei Oakdown.

Three millennia had passed since then and the hatred was virtually gone. The conflict had gone much deeper than that, it was second nature, regardless of the revelations that they had both been tricked and manipulated by the founder of Gallifrey himself the Master was always aiming to conquer and to rule those that he saw as inferior and the Doctor would always try to stop him. Maybe one day they would stop this unending conflict, and settle down to retire how they had started, as friends, blood brothers, but not yet. Even after three thousand years the Darkheart remained fresh in their minds, and until that was forgiven and forgotten, their conflict could never end. Ever.

[end of flashback]

Author's note: The event that finally seduced the Master to the dark side did involve a machine known as the Darkheart and ended with the Doctor imprisoning him in a black hole, this is just my interpretation of that event. If you research this you will find that it is described as a conflict with the second Doctor, but I am certain that this was not specified when I first came across it, and it works better for the story if it is a young Theta Sigma that it happens to.

The Master was also imprisoned on Shada, the only major difference being that (according the tardis wikia at least) the Time Lords deliberately released him on Earth to keep the Doctor busy, which doesn't really make sense to me and besides my way is more interesting.