The Doctor sat in the TARDIS thinking hard about the recent events. He tried to change a fixed point and went too far. He knew his song was ending soon. Rose, Martha, Donna all of them were gone. Donna was right he shouldn't travel alone. The Doctor sighed. Even though he had many friends he felt so alone. Time Lord Victorious? What was he thinking?

I have been alone for too long." thought the Doctor. "Maybe I should try to find another companion?" the Doctor shook his head. "No, after all in the end everyone leaves. I seem to ruin everyone who meets me." The Doctor got up from his chair.
"So where should we go old girl?" asked the Doctor. The TARDIS just groaned. "I don't know you usually take me places!" said The Doctor. All of a sudden the TARDIS took flight.
"Um ok I guess you are taking me somewhere. Can it be someplace nice please?" asked the Doctor. The TARDIS landed. "Alright let's see where you took me this time." said The Doctor as he put on his trench coat. When he opened the TARDIS doors he didn't expect to see an old junkyard.
"Why here?" asked the Doctor. The TARDIS didn't reply. The Doctor sighed. "I'm guessing something important is going to happen here so you want me to help in any way I can. Fine, I don't mind strolling around a bit." The Doctor walked out of the TARDIS shutting its doors behind him. As he walked he saw usual things you'd find at a junkyard. An old red lamp, some tires, an old blue couch, there were some stairs leading up to a second level. Next to those stairs was a phone booth. As the Doctor walked up the stairs he heard a mew.
"A little kitty is here?" thought the Doctor. It wasn't unusual for a cat to be in a junkyard, but for some reason the Doctor wanted to find this cat after all he could use some company. "Hello little kitty where are you?" asked the Doctor. He finished climbing the stairs. He saw on the second level a crane. On that crane he saw a tiny black kitten wearing a red scarf. "Hello! I'm the Doctor! Do you mind coming down and saying hello?" said the Doctor. To the Doctor's surprise the kitten climbed down and walked up to him.

Sissel had been alone for the past couple of years. Lynne moved away. Detective Jowd died of old age. Kamila became a mystery novelist and married. After a while she became older and died of old age. Yomiel happily lived with his fiancé now wife for many years but Sissel didn't know what happened to him. While Sissel remained an immortal kitten with ghost tricks. All their deaths he couldn't save. Of course Sissel understood they couldn't be around forever. Still he was immortal and alone. He still saves people's lives. After all there was nothing else he could really do. Tonight he felt like hanging around in the junkyard where he would've lost his life in an alternate time line. He remembered Ray who really was an alternate Missile. Sissel smiled. They had great times together didn't they? They helped create this better time line where just this once everybody lived. Sissel really missed the courageous Pomeranian. Really to be pretty honest he missed them all. Sissel stood on top of the crane staring at the stars. He started to understand how Yomiel felt in that alternate time line. Sissel was happy though. How he changed all of their fates, and he'll keep changing fates too.
"Thank you guys! I miss you! Wished I had someone to be with though." thought Sissel. But just as he was thinking this he heard someone talking.
"Hello I'm the Doctor! Do you mind coming down and saying hello?" Sissel looked down. There was an odd male human in a brown pinstripe suit and trench coat. He had messy brown hair and wore red shoes. He was looking up at him.
"Doctor Who?" thought Sissel. Curious to who this man was he climbed down the crane to greet him. The strange man had a surprised look on his face when Sissel sat at his feet. Then Sissel noticed something odd about the man. He had a core. " What? This man has died before? If he did who saved him and how?" thought Sissel. "Maybe I should go talk to him using his core?" Sissel went into the Ghost World and went into the man's core.
"Whoa where are we?" said the Man.
"Um...we're in the Ghost World. Apparently you've been here before." said Sissel.
"The Ghost World? How fascinating! Wait does that mean I'm dead? How come I didn't regenerate? And why am I talking to a cat?" asked the man.
"Regenerate? What's that? And no you're not dead. At least I don't think you are." said Sissel. " I'm Sissel, an immortal black kitten over fifty years old. I can use abilities called Ghost Tricks which help me manipulate nonliving objects."
"Well hello Sissel! I'm the Doctor." said the man.
"Really sir, doctor who?" asked Sissel.
"Just the Doctor." he said.
"So what does regenerate mean? And where did you come from? Why are you here in this junkyard so late at night? Why do you have a core?" asked Sissel.
" Well I might as well not even bother lying to you so I'll just tell you. I'm a time lord from the planet Galifrey. I'm 905 years old. I'm also a time traveler in a machine called the TARDIS. Time and Relative Dimensions in Space. Well it's not really mine I sort of stole it." explained the Doctor.
"You still didn't tell me what regenerate means." said Sissel.
"Or why you're here, or why you have a core."
"What's a core?" asked the Doctor.
"A core is something I could go on using my ghost tricks. People who have been saved from death and were awake during that time develop a core. I can also talk to them too." explained Sissel.
"Saved from death?" asked the Doctor. Sissel sighed. He explained to the Doctor all about his ghost tricks. Rewinding 4 minutes in time to save someone from death and traveling over phone wires.
"Interesting! Powers of the dead? That's brilliant! How did you get those ghost tricks though? And how did you become immortal?" asked the Doctor.
"I'll tell you if you tell me what regenerate means first." said Sissel.
"Fine it's only fair after all." said the Doctor. " You see my people the time lords including myself can do something to cheat death so to speak. Its called regeneration when all the cells on our bodies renew. However, it changes our face and personality. We can only do this 12 times. I'm on my tenth face you see." explained the Doctor.
"So you're kind of immortal but not really?" asked Sissel.
"Yeah that sums it up." said the Doctor.
"So I guess when you regenerate you develop a core. Interesting." said Sissel.
"Well actually this face regenerated twice. I didn't want to go just yet." said the Doctor.
"Ok, maybe that's why you developed a core because you've kept your tenth face despite regenerating again." said Sissel. " That still doesn't explain why you're here in the first place." The Doctor all of a sudden looked ashamed of something. "Um...Doctor you ok?" asked Sissel. " You really don't have to explain if you don't want to."
"No no you asked and I promised to tell you." said The Doctor. He explained all the events at on Mars in 2059. He even told Sissel about all his companions and adventures with them.
"Well thank you for telling me Doctor. Although I think you told me a lot more than I wanted to know." said Sissel. The Doctor looked like he was fighting tears but he still tried to keep a smile. " You know Doctor I sort of know how you feel. I had a friend in an alternate time line. He was immortal and had ghost tricks too, but everyone he knew was gone. His life that was going so well vanished. I was the only one who kept him company. He couldn't feel pain nor can he feel the sun's warm rays, or the wind's chill. Even though I was there he still did horrible actions trying to seek revenge. He was alone for too long Doctor. I think you need to travel with someone. That lady your companion Donna right? Shes right." said Sissel.
"Alternate time line? Do you mean alternate universe?" asked the Doctor.
"It's very complicated." said Sissel. " My point is you need to travel with someone."
"Yeah but everyone I come in contact with I seem to ruin their lives!" said The Doctor.
"No you didn't! You made them better Doctor! And they saved you!" said Sissel. " Yeah you really do need moral support. Why don't I travel with you for a while?" asked Sissel. The Doctor stared at him.
"But I'd probably ruin your life too Sissel. And how did I make them better in anyway?" asked the Doctor.
"Well first of all I'm immortal so really I don't think you can ruin my life much. Second if you never met Rose Tyler that day in the shop what would've happened? The autons would've invaded Earth and kill everyone, and you would be dead too. You taught her there's more to life than eating, sleeping, and working. She made you better too! Then there's Martha! She saved your hide on multiple occasions. Martha learned to care more for her family. Donna well sure she doesn't remember anything but you taught her she matters! And don't get me started on your other companions!" said Sissel. " You need someone Doctor. I'm afraid if you travel too long alone you'd end up like my friend in the alternate time line."
"Sissel what about your family? I know you have one." asked the Doctor.
"They're all gone Doctor. I can't prevent old age." said Sissel. The Doctor stared at him.
"Fine I guess a trip or two wouldn't hurt." said the Doctor." You still didn't tell me how you became immortal Sissel.
"Oh right right. Well about say 50 some years ago a meteorite fell into a park. I was there and one of the shards pierced me and killed me, but I'm still alive and with ghost powers." explained Sissel.
"So um...can we get out of this ghost world now?"
"Oh um yes Doctor!" said Sissel. They returned to the normal world.

"How long have we been gone?" asked the Doctor.
"No time has passed, because you see in the ghost world time doesn't flow." said Sissel.
"How come I didn't even notice! Some time lord I am." said the Doctor.
"You've never been to the ghost world until now. Maybe you were distracted by that?" said Sissel.
"Well Sissel you sure you want to travel with me?" asked the Doctor.
"Yes Doctor you're not going to change my mind." said Sissel. Sissel hopped onto the Doctor's shoulder.
"Well Sissel allons-y!" said the Doctor as he ran to the TARDIS.

"Did you have to run?" asked Sissel hanging on to the Doctor's shoulder for dear life or death or something.
"Oh yes! Sissel you must get used to that. This life has lots of running involved!" said the Doctor. The Doctor and Sissel walked into the TARDIS.
"Wow this thing really is bigger on the inside!" said Sissel.
"Really I haven't noticed!" said the Doctor sarcastically. Sissel purred as he jumped off the Doctor's shoulder.
"Well Doctor I can't wait to see where you take me." said Sissel. The Doctor smiled. Sissel noticed the Doctor's sad eyes were a little brighter. He could have sworn he heard the Doctor say, " Thank you old girl." as he piloted the TARDIS.