Note: For Rose, this starts sometime after Doomsday, but before Turn Left/Journey's End. For the Fifth Doctor, this fanfic starts both directly after Time Flight and after Enlightenment (it's a bit timey-wimey. Just read and you'll understand what I mean… I hope). For the Tenth Doctor, this starts sometime after Pompeii but before Turn Left.

Many thanks to my beta Hudine for helping me with this story.

Spoiler Warning: Huge spoilers for Arc of Infinity. If you haven't seen it and don't mind being spoiled, go all the way down to the A/N at the bottom of this chapter for a brief summary because you're going to need it to understand this story. Also, somewhat minor spoilers for Time Flight, Terminus, Enlightenment, and obviously, Doomsday, though you don't need to have watched Time Flight, Terminus, or Enlightenment to understand this story.

Disclaimer: I don't own Doctor Who. I make no money out of this.

Chapter 1

So, the boy turned against him. He supposed, he should have known better than to use a simple-minded mortal to do his bidding. What was that Earth saying again? Ah, yes. If you want something done right, you've got to do it yourself.

He'd had enough of using mortals to do his work. They hardly ever get the job done right. Worse yet, they gain a conscience and turn against him. No matter. He could always try again.

Hmm… try again… now there's an idea.

He made a mistake with Turlough. Perhaps he should have taken the boy out of the equation altogether. Yes, that seemed like a good idea. And, just in case, he ought to get rid of the Doctor's other companions as well. It wouldn't do for them to interfere with his plans.

With an evil grin, the Black Guardian looked at the timeline, then decided to give the TARDIS a little nudge.

oOo

The Doctor and Nyssa finally left Heathrow after solving the entire fiasco with the missing planes and the Master, leaving Tegan behind in her proper time and place, just as she had always wanted. After all her complaining, Tegan would no doubt be happy to finally be back home. The Doctor sighed a breath of relief once the TARDIS was safely in the time vortex. Perhaps, with Tegan gone, he could finally have some peace and quiet around here. Or at the very least, be able to go somewhere without Tegan complaining that it wasn't Heathrow.

"Right, then. Where to next?" The Doctor said to Nyssa. "We could go to the moon of Poosh. They have some of the most fantastic swimming pools. We could go for a swim."

A light flashed on the console. He glanced at the small monitor and saw a message from his TARDIS, reminding him that the the audio link-up has been broken for some time now and could he please stop procrastinating and do the repairs already?

"Or, we could stay in the vortex and do some repairs," Nyssa said while glancing at the monitor.

"Ah. Yes. Good idea." The Doctor nodded. "Would you mind fetching my tool box? It should be in the storage room."

Nyssa left to fetch his tool box while the Doctor went to open one of the roundels on the wall which hid the circuitry for the scanner. He took out the audio interface and examined it. It was quite old. He hadn't replaced it in, well… ever, really. This was the original audio interface that came with the TARDIS when he first stole away with her. No wonder it was breaking down. Perhaps it's time to get a new one. But for now, a simple fix ought to do it, if only Nyssa would return quickly with his tool box.

Just then, Nyssa finally returned to the console room carrying his tool box, which she set down on the floor next to him. He dug around for his tools and quickly started repairing the audio interface. He finished a few minutes later, but not without some admonishment from Nyssa for not doing the repairs sooner.

Time to test if the audio link-up worked.

Suddenly, the TARDIS shook violently. The Doctor raced to the smaller monitor on the console to find out what happened.

"Doctor!" Nyssa called out from behind him. The Doctor turned and saw her pointing at the scanner on the wall behind him. He turned to look at the large monitor and saw a flat-looking space ship on what seemed to be a collision course with the TARDIS.

"It's heading towards us! We've got to get out of the way!" Nyssa cried out.

The Doctor jumped into action.

"Hold this steady!" He placed Nyssa's hand on the two buttons that would initialize the microjump before racing to the other side to control the helmic regulator to make sure that the microjump would land them inside the ship. Moments later, he felt the TARDIS land. He looked at the scanner and breathed a sigh of relief. Microjumps were rather tricky. A slip of the hand could land them too far in space or time.

"Where are we?" Nyssa asked as she turned to look at the scanner and saw that they were in a metallic corridor with images of skulls painted on the doors.

"Inside the ship," he answered. Then, with a grin, he said, "Well, shall we take a look?"

oOo

The ship the Doctor and Nyssa had materialized into turned out to be Terminus, a ship carrying diseased passengers. Now that everything was sorted out, he had headed straight back to the TARDIS, only to have Nyssa stop him and tell him that she was staying behind.

With a heavy heart, he walked back to the TARDIS alone. He would miss Nyssa terribly, though he would never admit it out loud. He looked at the sterile white walls of the console room and sighed. He almost wished Tegan was still here. If nothing else, Tegan's presence would make the TARDIS feel less… empty. He started the dematerialization and let the TARDIS drift in the time vortex for awhile. With no companions filling the silence, he wasn't sure where to go, now.

Perhaps he ought to finish the other repairs Nyssa nagged him about earlier. The navigational systems really did need to be repaired. Then again, what's the point in repairing it? It's not as if he had any companions who needed to be taken back to the correct time and place.

Perhaps it's time to find a new traveling companion. Perhaps someone who loved traveling and wouldn't mind the occasional danger. Nyssa had been a wonderful companion. He really would miss her calm presence and brilliance. He wondered if he could find another companion like her. Or at least, someone who wouldn't complain every time he landed in the wrong time and place.

Where should he go, then? Earth? Many of his companions came from there. Then again, some of his most brilliant companions came from other places, such as Traken. Unfortunately, Traken was gone, which meant he had to find some other place to find a new companion.

With that thought in mind, he set the destination at random and hoped for the best.

Suddenly, the warning light flashed on the console. The Doctor raced to the small monitor and saw that the sensors detected a massive source of radiation. Alarmed, he raced to the other side of the console and tried to change course, but before he could do so, an extra-dimensional energy materialized in the TARDIS. Sensing danger, the Doctor ran out of the console room in vain efforts to outrun it, but the energy source caught him. The Doctor gasped as he felt a strong presence enter his body. The Doctor fought against the creature and concentrated on shielding his mind and expelling it. Minutes passed as the two fought for control over his body.

With a burst of willpower, the Doctor expelled the creature from his body. As the creature faded away, the Doctor felt his mind grew heavy. He swayed, then fell as he lost consciousness.

Meanwhile, the TARDIS was hurtling on towards the massive source of radiation. She tried to flee and slipped into a dead region of space known in ancient times as the Arc of Infinity, rumored to be a gateway to other dimensions. As she continued to flee the radiation, she slipped into one of the open gateways and found herself hurtling through the void and into another universe.

The screams of the TARDIS as she felt her life force draining away went unheard by her unconscious Thief.

Meanwhile, back on Gallifrey, the creature's attempts was not left unnoticed by the Time Lord Council. In a desperate attempt to prevent disaster, they tried vainly to recall the Doctor's TARDIS back to Gallifrey, only to be puzzled when the TARDIS suddenly disappeared from their scans.

oOo

Donna watched her skinny, pinstriped Doctor race around the console as if his trouser's on fire. He jumped around, flipping switches and levers, cranking what looked like a bicycle pump and spinning a crystal ball like hyperactive kid. This time, they were headed for some tropical planet whose named started with Cari or Carsi-something. She never really could remember the name since it was so bloody long.

Suddenly, the lights in the TARDIS flickered. An odd gong started chiming. The Doctor froze. His eyes widened in horror.

"What's going on? What's that noise? Doctor?" Donna looked at him in panic.

"That was the cloister bell. Something's wrong," said the Doctor. Suddenly, he froze again. "No. No no no no no!"

"What? What is it?" Donna's eyes widened in alarm. When the Doctor didn't answer, she slapped him and yelled, "Oi! Spaceman! Snap out of it!"

"Ow! What was that for?" The Doctor rubbed his cheeks and pouted at Donna.

"Tell. Me. What's. Going. On!" Donna glared at him.

The Doctor opened his mouth to answer, but suddenly, all the lights in the TARDIS went out completely. The time rotor slowed to a halt. The hum of the TARDIS pulsed lower and lower before going out completely, leaving them in complete and utter darkness.

"No no no no no! Don't do this!" The Doctor said. Donna could hear frantic shuffling which told her that the Doctor was probably racing around the console trying to undo whatever happened. There was a whirr and a flash of blue light as the Doctor turned on his sonic screwdriver and pointed it at the console. Then it was dark again. She could hear his footsteps banging across the metal grating as he ran around the console room. He turned his sonic screwdriver again and another flash of blue light filled the room. This time, Donna could see that he was on the other side of the control room, crouching down over a section of the grating that he had just pulled off the floor.

"Nothing. There's nothing! Not even a tiny blip!" The Doctor's voice was laced with frustration.

"Doctor? What's happening?" Donna asked. She didn't dare move from her spot, lest she trip over something or worse, fall into that gap in the grating that the Doctor had just made.

"She's dead. The TARDIS is dead," the Doctor said forlornly.

Donna's eyes widened. "What do you mean, dead?"

Instead of a proper answer, she heard a thud, then… silence.

"Doctor?" Donna called out. When he didn't answer, she called again frantically. "Doctor?!"

Still no answer.

Panicking, Donna crawled along the grating to where she had last seen him. She stretched out her hand to feel around her and bumped into a warm, soft fabric. She felt around it and noticed that it was a leg.

"Doctor!" Donna's eyes widened. She crawled over to him. At least, she hoped it was him and not some unknown alien who managed to sneak inside the TARDIS. She shook what she assumed to be his shoulders, but the Doctor didn't stir. Groaning in frustration, she felt around for his pockets. She had seen him stuff all sorts of junk into those bigger-on-the-inside pockets of his. With any luck, he might just have a torch in there somewhere.

As she felt her way inside his massive pockets, she felt something large, metallic, and cylindrical. Whatever it was, she hoped it was a torch. She took it out, felt around for a switch, then flipped it on. Light streamed out of the other end.

"Finally!" Donna muttered in relief, thankful that it was indeed a torch and not some alien weaponry that could potentially get her blown to pieces. She shone her torch on the Doctor and found him unconscious. Had he hit his head? Donna flipped his head to the other side, but found no bruises or blood.

"Doctor? Doctor!" Donna shook his shoulders as she tried to wake him up again, but the stubborn alien remained unconscious. She scowled, then took a deep breath and said, "Fine. You asked for it, Spaceman. Don't blame me if you wake up with a sore cheek."

She raised her hand, then gave him a good slap on the cheek.

He still didn't wake up, though his cheeks were now sporting a nice red hand print. He was definitely not going to be happy when he woke up— if he woke up.

Frustrated, Donna threw her arms up and sighed. "Well, that's just wizard! What am I going to do now?"

oOo

Parallel London, mid-August, 2015. It was the 5th year anniversary of the day Rose arrived in this universe with her mum. Five years since Canary Wharf. Every year on this date, Rose would take the day off and come here to remember. And to hope.

It had been five years since she and Jackie arrived in this universe. Five and a half since Rose, the Doctor, and Mickey first came here by accident and helped stop the Cybermen from converting all of London. It was only after she and Jackie settled here in this universe that Rose found out that the Lumic incident had been three years ago for Pete whereas for her, only six months had passed since that time. Apparently, this universe was running ahead of her own.

She wondered how many years had passed for the Doctor since they last saw each other. Had he found someone else to travel with? Had he regenerated?

Sighing, she walked up to the river's edge and stared at the very scene that once made the three of them look up in surprise. Zeppelins floated over the river Thames. A beautiful sight, as long as she tried not to remember that it meant she was now forever separated from her Doctor.

Suddenly, a hauntingly familiar sound filled the air. She hastily took out her key and noticed it glowing. Rose's eyes widened. Rose scanned her gaze around the area and saw the TARDIS materialize on the very spot that she had materialized in years ago.

oOoOoOo

A/N:

Arc Of Infinity: Basically, all you needed to know was that there was this creature made out of anti-matter. This creature was from another dimension and used something called the Arc of Infinity (also known as Rondel) to come into our dimension. But in our dimension, he had no physical form, so he needed to take over someone's body in order to exist here. So, he tried to possess the Fifth Doctor in a process called a "bonding". But the bonding failed, so the creature couldn't possess the Doctor. The Time Lord Council in Gallifrey somehow knew about the creature and the bonding. They wanted to stop the creature from bonding with the Doctor and coming into this dimension. So, they tried to recall the Doctor's TARDIS back to Gallifrey.

That said, you really need to watch Arc of Infinity. It's a great episode and Nyssa kicks ass in that one.

Oh, and in case it wasn't clear, the first scene with the Black Guardian is set after Enlightenment. The one with the Fifth Doctor and Nyssa starts directly after Time Flight, thereby skipping episodes Arc Of Infinity through Mawdryn Undead so that Tegan never rejoined the Doctor and Turlough never came on board. After Nyssa left, we go back to the beginning of the Arc Of Infinity episode, except Nyssa wasn't around this time. So, yeah, it's a bit timey-wimey cause I rearranged the episodes a bit.