He could see it. A thousand year old man flying through the galaxy with his daughter. When he closed his eyes, he could've seen them together, they could've had incredible adventures. But when he opens them, all he hears is a gunshot. A man, with a gun. Years of happiness, years of having someone to share his troubles with, gone, in an instant.
He had gone to a planet. There wasn't any real reason why, though if he had to name a cause his ship's constantly malfunctioning navigational system would be a good thing to blame. There was a war, between the colonists on a planet. When he had shown up, he had ended up having to stop both sides from outright massacring each other, and in the process, discovered that they were using "progenitor technology" to create clones of themselves, to keep up their dwindling numbers of troops. It was impressive technology, but it had a few flaws.
The first was that this technology accelerated the war. What took days in reality, was generations to the colonist's clones, so their war evolved from a squabble over resources to a war of mutual destruction, because neither side could recall what the war was about, let alone stop it. They eventually lost their knowledge of their technology, thinking that a terraforming technology called "The Source" was some mystical power source.
The second was that this technology didn't need the user's consent to use. So the Doctor ended up contributing to the human side against his will. That contribution was a...daughter. Called Jenny. She was...beautiful. Dangerous, but had a zeal for life that he had never seen before burning bright in her short time in the universe. Like those of his species, she had two hearts, but unlike his species, she couldn't regenerate. His species, when dying, would be reborn, like a phoenix of earth folklore, in a cascade of energy. But Jenny couldn't. She was so much like him. But she wasn't. So when she took a bullet to her chest for him, she didn't get back up.
Sometimes, he felt so helpless. He was a Timelord, he travelled through time like most travel through interstate traffic, he wanted to go back, to change what happened, so badly, but he couldn't. Paradoxes could form if he wasn't careful, time could fracture. He knew this from experience. Time is malleable, but to mold it was to change the fabric of the universe. But he could.
When he closed his eyes, he could still see her face, as he regaled her with stories of his ship that could travel through space and time, wonders beyond her comprehension, things that nobody on her planet had ever seen before. He could see a future. One where he wasn't the last being in the universe with two hearts left.
But he had to open his eyes sometimes. His slightly blurred vision showed that he was right where he was when he closed them. Hanging like a vulture over the controls of his ship.
"Doctor?" Said a woman to his left.
Donna Noble, the latest in a line of friends, or as he called them, companions, that accompanied him through his journeys. His companions were mostly human, often not, but were always a little crazy. Donna was no exception. She had accompanied him through some particularly trying times, but then again, most of them did too. In the deepest darkest recesses of his soul, he'd even admit that sometimes they blended together as even his impressive memory was corrupted by age, an age that most of humanity would never experience.
But he still kept bringing them along, he didn't really know why, he supposed they kept a sense of wonder in the Tardis, his ship. A glow, not unlike the one that people say adorn parent's faces. Then again, those effects could also apply to him. But for the first time in nearly a hundred years, he didn't want a companion.
"Doctor? You're really starting to look bad" "Oh, sorry Donna, was a bit unfocused, I'm parking the Tardis at your house now" He could hear the whooshing noise that almost always accompanied his blue police box materializing, and he walked to the door, opening it to her doorstep.
"Doctor." "Well, we're here now, I believe this is your stop, Earth, 21st century, England." "Doctor, I don't think you're okay." This caught him off guard, though her firmly kept his eyes anywhere but his friend. "Donna, I'm fine." Donna looked at him with a sideways glance. "Fine. You stubborn man. Just know, I'm here for you if you need it, okay?" The Doctor looked at her gently "Thanks, but I don't need help, I'm a Timelord, remember?" "Even a lord of time has a heart" Donna said softly as she left the ship "Don't do anything stupid. You do stupid things when I'm not around!" she yelled as she walked to her porch. As soon as he shut the supposedly wooden doors behind her, he slumped on the doors to the Tardis, not even getting up to go to the console, pointing his sonic screwdriver at the console, which whirred to life, and the whooshing sound returned as the Tardis and it's sole occupant phased out of this time and location. To be really honest, he didn't even choose an era, he just left and fled to the cold abyss of space.
From his resting place on the floor his vision began to cloud as he began to replay Jenny's final moments in his head. How she bravely jumped in front of him to take a bullet for him. He wished she hadn't done it. He could handle a regeneration, but the pain he felt from her passing was worse. As his vision blurred his line of thinking changed back and the temptation
He began to go over the angles, the contours of the scene. The direction of the bullet, the angle of the gun. The force it would've taken to move Jenny out of the way. There was so much he could've done to save her. Knocked her out of the way, knocked out General Cobb, just been a little bit faster…
But all of those required foreknowledge, and though he was a Timelord, or, as he sadly corrected himself, the Timelord now, even he had rules to timetravel. He was a time traveller, that gave him certain responsibilities. Anything he witnesses is locked in time. So everything that happened had to have happened, or there would be consequences. He couldn't go back and change what he saw. Her death wasn't his fault he kept telling himself. Maybe he'd believe it someday.
But there are loopholes. If he didn't see himself save her, he could save Jenny! The Doctor ruminated as he began to make a plan. It would be simple, he told himself, just create a form of cloaking technology that wouldn't be detectable by the Tardis alarms, invent a chronal freezer to slow down the bullet, and so I can't see what's going on, and replace it with something nonlethal, it's BRILLIANT. The Doctor began to go over all of his plans in his head, he was formulating an entirely new realm of mathematics to figure out how to build a chronal freezer and a cloaking device.
He was walking into the bowels of the Tardis, to the storage lockers with his collective junk and treasures of a thousand years of travelling. As he walked along, he began to realize that both a chronal freezer and a cloaking device of this scale would be incredibly hard to make, and would require years of work and effort. As he came into a foggier area of the Tardis's rooms, he began to realize that what he was proposing would take much longer than a few years, it would be decades before any of the parts of his project would work, especially since he realized that he would have to freeze all of time for this to work, and that would require more power.
As he walks along, he crashes into someone, and falls back. He immediately pulls out his sonic screwdriver, and the old man he bumped into was scrabbling on the ground picking up parts. "Who the hell are you?" "Who the hell am I?" said the old man. "I'm the bloody Doctor!"
The younger Doctor looked at him with questioning eyes "No, I'm the Doctor, you're on my Tardis". "Pfft, please, it's my Tardis. Now knock it off. I'm almost done saving her." He continued trying to grab parts that were scattered on the floor, scattering them even more as he crawled on the ground. "No, wait, I...got it!" the old man held up a small, nondescript, metal screwdriver. "What are you-" "Finally, this is the last part, I can save her" "Her, do you mean-" "Clara, I can finally save you. And you too Donna, and you Rose, I can save all of you, just one at a time, starting with you Jenny, don't worry" The Doctor watched as the older man ran back into what seemed like a swirling fog, scattering all of the other pieces that he dropped before as they rolled into the fog, lost to time.
And then The Doctor woke up. He was slumped on the doorframe of the Tardis. Judging by the crick in his neck, he had been there for a few hours at least. He slowly, and groggily walked up to the control panels in the center of the room. He looked at the various displays on his screens, and pulled up a directory of planets with parts necessary for chronal manipulation on them. Chorus 12 had good flux capacitors, he'd need that if he were to make a chronal freezer.
But his finger stopped, hovering over the button that would've automatically put in the coordinates. He went over the calculations in his head, double checking that they would take years to complete, and had a vision of the old doctor again. The decrepit old man, gone mad alone, flailing in the darkness. He then remembered Jenny, how she smiled, and was so tough and rugged, and felt a stab of pain just thinking about her. But then he remembered how brightly she shone despite such a short life, and for the first time since she died, smiled back.
He gradually pulled his hand back from the screen. He powered down the directory, and got up to manually put in coordinates with a complex set of joysticks, bells, and whistles. He was aiming his time machine at about 15 minutes after her death, so he could assist with the burial. He knew he had a few proper Timelord antiques somewhere on the Tardis somewhere, he'd bury it with her, she deserved to be connected with her heritage.
But his Tardis did always have a terrible navigational system. She wasn't off by much this time, normally she would be off by a few hundred miles, or worse, a few dozen years. This time was only a few minutes, so he ended up about a minute or so after his past self had left.
That's when he saw it. Jenny couldn't regenerate, she didn't get that from him, but it appeared she got his luck. The terraforming technology revived her from the dead, just after he left. One bad thing about time travel, once you leave, it's sometimes hard to get word back. But he came back. And he watched his daughter take off into the great unknown to explore the universe just like him. So he followed her. And she found him waiting at the first rock she stopped on with a hug and a smile as they tearfully embraced.