The Time War became an obsession for the Master. He became determined to find out every detail about it. He forced the Doctor to talk about it, more so than the Doctor was willing and rarely let the subject lay. At times the Master would listen calming, give the Doctor time to get his words out, sometimes even going as far as to wrap his arms around him as he spoke. Other times he was less kind, pinning the Doctor to the wall, forcing him to meet his eyes as he spoke, beating the words out of him. At times the Doctor was glad for opportunity to explain how he was feeling, glad to be able to talk and hold nothing back, glad he didn't have to sugar coat it, glad to have someone who could listen and understand. Other times the Doctor wished the Master would just let it go, let him stop thinking about it, let him stop hurting but he knew that wouldn't happen and for the most part he accepted that. He grew used to it.
But it wasn't just the Doctor's words the Master wanted. He wanted to see the remains of the planets that got involved, the ones other than Gallifrey which were left a cindered ball cycling defiant suns and he took the Doctor to each of them. Watching the emptiness, imagining the deaths. He took the Doctor to planets which had taken in survivors of the Time War, members of species who had fought but left before it was too late. He listened to any survivor who would talk to him, taking in the different stories, the different views of the same horrific war. Each time the Doctor just stood there quietly, trying not to listen, trying not to remember but being forced back onto Gallifrey, forced to the worst moments of his life each time it was mentioned.
In his desperate quest for knowledge the Master found out about the times the Daleks returned after the Time War and though convinced there was none left in the universe, they came across one lone Dalek on an abandoned planet, preparing for a fleet that would never come. When faced with the Dalek, the Doctor saw an anger in the Master which went beyond everything else everything else he had ever seen. The Master destroyed the Dalek, killing it within moments of seeing it, shouting almost illegibly about the destruction of Gallifrey and continuing his frenzied attack long after it was obvious it was dead. The Doctor stayed back when this happened, avoiding the Master for a long while after it to give him time to calm down.
Yet it was never quite enough, despite dragging the Doctor all other the universe to see the aftermath and hear the stories and legends of the Time War, it was never enough for the Master. He still wanted more, he still needed more. He needed to know everything, every tiny little detail, but he knew knowing wouldn't be enough. He needed more than that, he needed to feel it.
"Theta?"
The Doctor looked up from his cross-legged seat on the chairs by the controls to find the Master watching him. He tried to read the Master's blank expression but couldn't, "Yes, Koschei?" he replied softly.
The Master's expression turned to a glare for a brief moment. They hadn't come to any agreeable solution regarding their old names; the Doctor had come to accept the Master calling him Theta because he had no choice in the matter, while a part of him was glad of it for the old familiarity and safety in it. The Master on the other hand still hated the use of his old name, feeling it lacked the power "The Master" held, but for the most part allowed the Doctor to use it as long as it wasn't too often. The glare only lasted a moment before the Master's expression became unreadable again.
"You're going to show me," he told the Doctor simply.
The Doctor looked at him in confusion, his mind instantly worked out that this was something to do with the Time War but beyond that he didn't know what the Master meant. "Show you what?"
"The War," the Master continued to speak simply.
"What do you-" the Doctor broke off from asking what he meant when the realisation dawned on him. He stood up and stepped back despite the fact that the Master hadn't moved towards him, "No. That's not going to happen. No way."
This time when the Master glared at him it remained on his face, "You haven't got a choice in this, Theta."
The Doctor glared right back at him, "You can drag me all around the universe, you can force me to tell you ever little detail, everything I know, everything I saw, you can hit me when you're angry, I don't care but you are not seeing the War."
The Master stepped around the console towards the Doctor, who took another step back, "Again, I feel the need to tell you, you haven't got a choice in this."
The Doctor hesitated for a moment before saying, "You'll have to find me first," and bolting off deeper into the TARDIS.
"Oh come now, Theta, that's just childish," the Master rolled his eyes and called after him.
The Doctor knew it was childish, but he was rather be childish that allow the Master to witness the Time War from his mind. He knew the Master felt like he needed to see it and part of him felt selfish for being against showing him, part of him felt like he owed the Master it since it was his fault Gallifrey was no longer there. But that was the smaller part of him, a bigger part knew the Master would regret it once he had seen it, the bigger part knew that once it was seen it would be burnt into the Master's memories forever and he would never be free from it. He ran deep into the TARDIS to the point where he almost got himself lost, but that was good, if he wasn't sure of the way back, it would be difficult for the Master to find him.
At least that's what he thought, he was proven wrong pretty much as soon as he went to relax. The Master grabbed the Doctor's arm and turned him to face him. The Doctor couldn't stop his hearts and breath from quickening as he did.
"Did you really think you'd be able to hide from me, Theta? Really?" he asked, anger clear in his voice.
The Doctor attempted to pull away from him but the Master wouldn't let him move.
"Now I will tell you one final time, you are going to show me the Time War," the Master repeated. "Is that clear?"
"Crystal," the Doctor replied bitterly, succeeding in pulling away this time. "It's still not going to happen."
The Master smacked him across the face, "I am the Master and you will do as I say."
"Not this time," the Doctor said defiantly.
"Really? You're not going to show me?" the Master asked and the Doctor shook his head, "You don't think I have the right to see what happened in the war that ended the life of my people and my planet?"
"You lost that right when you ran away."
The Master hit him again, this time in the stomach, "You know why I had to run."
"Yes. I do" the Doctor agreed, "And for the same reasons you aren't going to see it."
"You don't get to decide that, Theta."
"It's my mind. You can do whatever the hell you like and I know you will but you stay away from my mind," the Doctor insisted.
"No," was all the Master said in response before roughly grabbing the temples of the Doctor's head. "You're mine, Doctor, body and mind."
The Doctor struggled helplessly against the Master, "Get off."
The Master ignored him and concentrated with his whole mind on opening the connection between his mind and the Doctor's. The Doctor continued to struggle as the Master did this but the Master proved to be stronger and forced the merging of their minds. As he did so the Doctor let out the smallest of whimpers, his mind in screaming out in protest as being invaded against his will.
"It'll hurt less if you stop struggling, Theta," the Master said, directly into the Doctor's mind, the mental voice soft and soothing. The complete opposite of how the Master had been only moments before.
"I'll stop struggling when you get out of my head" the Doctor replied, bitterly. He closed his eyes to block out the image of what was around him and focus on his mind. He used all his strength to try and push the Master out but quickly realised that the Master's mind was stronger than his and was forcing its presence with more force than the Doctor had to force it out.
"Relax and it'll be all right," the Master told him.
The Doctor didn't reply. He was using all of his concentration to try and protect his mind from the Master's intrusion. He hasn't shared his mind with anyone since Reinette and he knew that the imaginary closed doors he had told her to think of wouldn't be enough to keep the Master out.
"What's wrong, Theta? You never used to have a problem with me being in your mind," the Master commented, almost but not quite distracting the Doctor from what he was doing. "You used to love it, being able to calm me down. See, Theta, I think you're just like me."
"Shut up," the Doctor told him irritably, his head aching from the effort of trying to protect itself and the pain of a foreign unwanted presence.
The Master ignored him, "I think you loved having control. You loved having that hold over me, back when we were young. You loved knowing that you were the only one who could calm me down, make it better. You loved being able to control me."
The Doctor took to ignore him, trying to block out his words but knowing there was no way when they were being said directly into his mind.
"Not so good now is it? Now the tables are turned, now it's me in control" the Master continued, rambling along as though he couldn't stop himself. "Now that I'm completely in control of you. Every little part of you is mine and there's not a damn thing you can do about it. You're my Doctor, my Theta, all mine."
The Doctor hoped that the Master would be too focused on what he was saying to notice the blocks he was putting up in his mind. The blocks he hoped would be strong enough to keep the Master from seeing what the Doctor desperately wanted to protect him from.
"And I'm going to see, Theta. You can't stop me from seeing. Nothing can stop me from seeing."
The Master stopped speaking to the Doctor's mind and took to wandering through it instead. It was but strange and familiar. A lot of the Master's own past was in the Doctor's mind and he knew that at another point he would return to the Doctor's mind and drag it up. What better way to get to the Doctor than show him all the ways he screwed up when they were first together? But for now he had a more important task at hand. The Time War was locked away in the Doctor's mind and he had to find it. He had to drag it out, he had to see it. He needed it; he needed to understand what happened to his planet, he needed to see what he had run away from.
He found wandering in the Doctor's mind was like walking through a forest. It was dark and should've been scary and yet there was something familiar and safe about it. All around him were the Doctor's memories, they were all open for him to look at, all but the one he was looking for. He was acutely aware of the Doctor's mind protesting to his presence but that was easy to ignore.
Eventually he came to what appeared to be a barbed wired fence. The Master looked past it and saw a dark building which appeared like a prison and knew that had to be where the Doctor was hiding the memories of the War. He knew the defences were more than just barbed wire but he also knew it wouldn't be nearly enough.
"Do you really think that's going to keep me out?" he asked, his voice tinged with amusement.
A/N: I came to this fic today all "I don't know what to write so I'll just do a filler-ending/epilogue thing and end it" and started that, then got the idea for the mind-intrusion and here we are with the story not ended =P. R&R. ly'all.