(This is intended to be an 8th Doctor fanfiction, but I decided not to specify which Doctor it was and leave it up to the reader.)
"Fight! Kill! Repeat! Die!" The Doctor stormed around the six different control panels of the TARDIS. "Is there nothing else the universe can do?" In somewhat of a tantrum, he kept flicking levers and pressing buttons, quicker and quicker and quicker, then finally slamming his hands down on the edges of the control panel. His head fell down to face the floor.
He took a deep breath and finally raised his head and stared at the glass pillar at the center of the TARDIS's control room. He spoke softly and calmly. "I admit it- all those years ago, I had given up. I had taken Susan down to Earth and stayed there because I thought there was nothing I could do. Then I met incredible people, from all over- you met them too, old girl! And I knew my mission was to rid this universe of the wars, the fights, the killing." The TARDIS landed and the Doctor strolled towards the door and opened it a crack.
An explosion outside, even through the small crack of space, threw him back towards the ground. He stumbled up again and glared outside. "Right now the universe is making it very very hard for me to not give up again!" He grabbed the door and slammed it shut as hard as he could, and the TARDIS bellowed in surprise. He sighed, put his back to the door, and slid to the floor. "Doesn't any part of the universe care about something other than its own benefit?" he moaned.
He then sprinted to the controls and set a new destination. He opened the door this time to find himself nearly shot in a gang war in the 21st Century. Again, he set another destination, over and over, each time slamming the door shut in indignation. Daleks shooting a child. A medieval army invading a castle. Someone struggling to escape the arms of a Weeping Angel. A man in a suit smiling and shaking someone's hand, then stabbing them with the other. Another bomb dropped from a plane. Another arrow fired from a crossbow. A meadow. The Doctor slammed the door shut once again, then suddenly opened it again.
A meadow. He walked out and smelled the breeze as the sun began its journey toward the horizon. An alien bird chirped its unique song in the distance. The Doctor spotted a rustling of leaves, then a group of blue, insect-like people emerged in a formation. The Malmooth, the Doctor remembered. A group of Zygon soldiers emerged from the other end of the meadow holding rifles in their hands. The Doctor shook his head and began to enter the TARDIS again.
At the doorway, he closed his ears and prepared for the sound of gunshots. He closed his eyes after a few seconds. More seconds passed. He slowly opened his eyes and turned around. The Zygon soldiers had dropped their rifles in front of them. He stood in shock for a moment, then ran through the tall grasses to meet with them.
"Why aren't you fighting anymore?" the Doctor confusedly asked one of the Malmooth.
"There was a man who showed up and told us to compromise," the Malmooth responded. "We thought it impossible, but with the help of a device he had we were able to cease fire and negotiate a peace treaty. He showed us both sides of the argument and we realized there was no reason to fight." He breathed in some fresh air. "I used to be a general- I feel like a weight has been lifted from my shoulders!"
"So do I," the Doctor said, not completely sure there wasn't some trick up the sleeve of the Zygons. "What- what device?"
"He never said what it was, but he left it with us in case of emergency. Said he could get another one." The Malmooth handed the Doctor a small pouch. He quickly opened it and held up the device. It was shaped like a stick, had a bulb at the end, and when the Doctor switched it on it made a buzzing noise.
He dropped the device to the ground and made his way back to the TARDIS. "Old girl," he said to the blue box, "maybe I will finish this mission someday after all."