The Doctor stayed hidden and listened for voices. Hearing none, he walked into the repair shop. No one was around. He quickly ran to the nearest vehicle. Finding it unlocked, he stepped inside, shutting the door behind him. He walked over to the main console, staring in confusion at the all the levers, running a hand through his gray hair. "How do you work one of these again? Where's that manual? Ah, here." He picked up a small booklet, that, as he opened it, revealed itself to be much longer, and thus more complicated, on the inside. The Doctor skimmed through the pages, while pulling at levers and pushing buttons. The space-time vehicle made a whooshing sound and disappeared.
The ship materialized, and the Doctor stepped outside. He was in a garden, but not just any garden. It was the garden from the Doctor's family estate. All was quiet. No one was around. He made his way to the house. Again, there was no one and all was quiet. Afraid to make a sound, the Doctor silently explored the rooms, so familiar, but at the same time, so indifferent to his worrying. He made his way to the banquet hall. And there he found them- lying in heaps across the floor. He rushed out of the room, and ran out of the house back into the garden. He leaned against the wall, unable to catch his breath. He knew that he could not go back inside with becoming sick. Tears streaked aross his cheeks- his family, that was his family. No more laughter, or kisses, or silly little chats. They were gone, taken from him. He was alone. He couldn't stay here, or they would find him, too.
He was walking back to the ship, knowing he would leave and never return, when he suddenly heard a faint sobbing. It was coming from the bushes. He went over to the sound and moved away a branch. He saw a small, huddled form of a girl; her eyes were tightly shut, and her arms were wrapped protectively around her body. "Susan," whispered the Doctor, reaching for her. The girl, at the feel of the Doctor's touch, started to thrash about in defense and managed to kick the Doctor in the shin. "Oomphf," he whimpered, but grabbed at her again. "Susan! Susan, it's me."
She opened her eyes and looked at the Doctor, suddenly realizing who he was. "Grandfather!" she said, hugging him tightly, afraid to let go.
"Hush, my child," he said, caressing her. "It's okay. I'm here." He picked her up and carried her back to the ship with him. He put her on a bed and she fell asleep, worn out from her tears. The Doctor walked back into the main console, leaving behind the home he was unable to save.
The Doctor stood alone in the main console. The TARDIS was empty apart from himself. He had no Companions. He didn't want any. "Can't hurt if there's no one to hurt," he thought, unsure if he was talking about himself or them. With no one to talk to, he was starting to feel lethargic, so he just went to bed.
The Doctor found himself in that long unvisited garden. All was quiet and still. He heard sobbing in the bushes and went over to them- no one was there. He heard the sobbing again, but now it was all around him. He started calling out for Susan. Out of nowhere, she appeared, but as she looked as he saw her when he left her on Earth to live her life with David. "Susan?" he said.
"Grandfather!" she called out. They rushed towards each other in a tight embrace.
"Oh, my dear little Susan," whispered the Doctor, not wanting to let go of her.
"Why did you leave me, Grandfather? Why didn't you save me?" she cried. But before the Doctor could answer, she suddenly disappeared from his sight and from his grasp. The sobs returned.
The Doctor awoke with a start. The dream bothered him the whole next day, and took up the majority of his thoughts. And the next night, he fell asleep again.
He was back in the garden. This time, Susan was there to greet him first off. "Grandfather, why didn't you save me?"
"I couldn't," he replied.
"Why?" she asked.
"I tried. I just couldn't."
Susan looked at him forlornly. "Do you remember when we left Gallifrey together, just the two of us? Then the TARDIS broke down on Earth, and by the time you had found the spare parts, I had begged that we might stay longer."
"I suppose I didn't think I was being fair to you, not being able to provide you with a stable home life."
"And I did yearn for a home," said Susan. "But I never could have abandoned you."
"I know," said the Doctor. "That's why I had to force you. I was doing what was best for you."
"I thought I was going to travel with you forever."
"You couldn't. Not if you wanted a home."
She stared straight into his eyes. "And have you saved my home? Have you saved Earth?"
He smiled. "Yes, Susan. I saved your home."
"Thank you, Grandfather." She gave him a kiss on the cheek.
The Doctor woke up and smiled. He went to the main console and found a picture of Earth on the scanners. "Yes, Susan. I saved your home."