PREVIOUSLY ON DOCTOR WHO:
After being captured by the Rani and used a test subject for her regeneration-themed experiments, the Doctor escaped back into his TARDIS with Clara, only for him to regenerate backwards into his Eleventh body, to Clara's surprise.
The Doctor rubbed his hands together. "Right then, let's see what we've got this time."
Clara stared deep into his face and covered her open mouth.
"What?" the Doctor asked. His Scottish accent was gone, too. "Don't tell me I'm deformed? Did the Rani alter my genetic code so that I'm a mutant now?"
Clara's hand dropped from her mouth. "It's you…" she finally managed to say.
"Well of course it's me," the Doctor said. "Who else would it be?"
He turned around and faced the monitor on his console, gazing into the semi-reflective surface. Once he saw his reflection, his face mirrored Clara's as he ran his fingers through his hair and around his face, as if inspected to make sure it was real.
"Oh…" the Doctor said. "It's me."
"How is this possible?" Clara asked. "You've regenerated backwards?"
"The Rani said that she was trying to find a way to control the regeneration process," the Doctor said, not taking his eyes off his reflection. "She mentioned that if the procedure on me worked, it would allow her to choose from any future or past regeneration to become. Looks like it worked – Blimey! I forgot how big this chin was!"
Clara's mouth twitched in a small grin. "Okay. Well, is this permanent?"
The Doctor turned around to face her. "I'm not sure. Once the Rani finds us, we'll get some answers from her."
The Doctor unbuttoned his coat and looked down at his dark coat and vest. "You know, it feels like this outfit's missing something." He rapidly snapped his fingers as his eyes drifted to the ceiling, his mind working in overdrive.
He snapped loudly and pointed at Clara. "I know."
He turned on his heels and dashed off down a corridor. He returned a moment later wearing a deep purple bow tie.
He gestured to the garment. "There we go. Bow ties are still cool, right?"
Clara smiled. "Always."
The Doctor smiled back and approached the door. "Now then, let's see where exactly we've landed. Haven't said this in a while, but…Geronimo."
He opened up the door and exited the TARDIS, Clara following. Outside was a green field stretching as far as the eye could see. A few trees dotted the landscape, and a stone castle stood against the sky in the distance.
The Doctor sniffed the air. "Looks to be 13th-century…Scotland, I'd say."
"Are we safe hiding here?" Clara asked.
"Probably not," the Doctor answered. "She's most likely locked onto our temporal signal as we speak. But at least we have a nice landscape."
Suddenly, a different noise filled the air. It sounded much like the TARDIS's materialization noise, but instead of grating and wheezing, it sounded smooth.
Clara and the Doctor turned around as an object materialized next to the blue box of the TARDIS. Its form was hard to make out at first, but when it solidified, the object appeared as a tall stone rectangle, its edges roughly cut.
A door opened along the side and the Rani stepped out, her face filled with anger.
She stormed up in front of the Doctor and Clara and looked at both of their faces. "Where is the Doctor?"
The Doctor spread his hands. "You're looking at him."
The Rani's eyes widened and her think eyebrows shot up her forehead. "What?"
"Clearly you don't recognize this face," the Doctor said. "Your experiment worked, Rani. I've regressed to one of my previous regenerations. Now you're going to turn me back to normal, now."
The angry tone in the Doctor's voice barely made the Rani flinch. "And why would I do that, Doctor?" the Rani asked. "The process was interrupted by your companion here." She spoke the word like it was poisonous.
"My experiment was left incomplete," she continued. "So you are going to get back on that operating table and let me finish, whether you co by choice or by force."
Suddenly, the Doctor's skin began to glow again with regeneration energy. His face lit up with satisfaction as he looked down at his glowing, shimmering body.
"You're regenerating again," Clara said.
"So I am." The Doctor looked at the Rani. "Looks like your little experiment was temporary, Rani."
As the golden light spread over his entire body, the Doctor said, "Here we go."
The regeneration was the same as before: a short, bright burst of light, and the Doctor stood with a new face.
But the face still wasn't the older face Clara was used to. His new face was thinner, with dark hair styled up in the front and long sideburns.
Clara recognized this face too, from an adventure where the Doctor met up with two of his past incarnations. This incarnation was known for wearing a pinstriped suit and converse shoes, but now he was still dressed in the Doctor's current dark navy ensemble.
"Well then," the Doctor said, turning to Clara. "Am I fixed?"
The Doctor furrowed his brow. "No, wait. I'm still not Scottish." His eyes widened. "Oh, wait! I know this voice!"
He reached into his pocket and pulled out a small pocket mirror. His eyes lit up in surprise – and what looked strangely like glee – when he looked at his reflection.
"Oh, this one again!" the Doctor said.
"I don't quite understand what's going on," the Rani said.
"It's another one of his older faces," Clara explained. "But other than that I'm still confused."
"There must still be a glitch in the experiment," the Rani said, scanning the Doctor's new face. "Your regenerative process is going in reverse because the process was incomplete, and it'll come at quicker intervals until you get down to your first body."
"What'll happen then?" Clara asked.
The Doctor looked at the Rani with demanding eyes. "Will I simply stay in that body forever?"
"I don't know," the Rani said.
"So are you going to fix this so that I can be normal again?" the Doctor asked.
"I can complete the experiment," the Rani said. "It should return you to the from you desire."
"But your experiment will be complete. You'll have the data you need."
"Naturally," the Rani said.
"In that case…" The Doctor leaned in and stuck his hands in his pockets. "Forget it."
The Rani arched her eyebrows and reached for something at her hip. "In that case, I shall take you by force. Again."
She grabbed something and lunged towards the Doctor, sticking something into his chest. There was an electronic buzzing coupled with the crackling of electricity, and the Rani convulsed before collapsing onto the ground.
Clara looked at the Doctor in shock as he smiled slightly at her. He pulled his hand out of his pocket and pulled out his sonic screwdriver, the end glowing with green light and buzzing.
The Doctor pulled his finger off the screwdriver's button. "Reversed the polarity on her stun-stick. She'll be out for a little bit."
"What are we going to do now?" Clara asked.
"Well…" The Doctor darted his eyes towards the large stone next to the TARDIS. "Her TARDIS is still here, and that machine she used on me is in her TARDIS. I say we infiltrate it and try and get me back to normal."
"Do we have to?" Clara asked coyly, eying the Doctor up and down. "This body's kinda cute."
The Doctor grinned ear-to-ear. "I know, right?"
He grabbed Clara's hand. "Come on. Allons-y."
The two of them ran towards through the door of the Rani's TARDIS and entered into her violet-lit console room. The Doctor loosened his bow tie and stuffed it into his pocket as they went. They ran down the corridor directly behind the center console and came to a fork in the hallway.
The Doctor looked left and then right, but he still seemed uncertain as to which way he should go.
"We should split up," the Doctor said. "We should be able to find the Rani's laboratory quicker that way. But don't stray too far. We still need to contact each other if one of us finds anything."
Clara nodded and as the Doctor let go of her hand. He sprinted down the left hallways while Clara escaped down the right one. A few doors lined both walls, and Clara looked into each one in search of the laboratory. The first one on her left led to a library, with skyscrapers of books leading to the seemingly endless ceiling. The next door was on he right, and it opened up to a completely white, sterile room with large roundels on the walls.
As Clara descended further down into the hallway, each door she entered resulted in disappointment. She discovered a kitchen, a room covered entirely in wall-to-wall monitors, and a swimming pool that seemed to stretch into infinity. But still, there was no laboratory to be found.
It wasn't until she reached the end of the hallway, before it took a sharp left turn, that she found the room in question. The operating table was in the center of the room, the wires from the console at the side still strung out onto the floor. Along the walls were various other machines and devices, from large television screens to machines that looked like heart monitors and message chairs, but Clara was sure that each one was deadly.
A smile crossed her face as she peaked out of the doorway. "Doctor!" she hollered down the hall. "Doctor, come quick! I've found it!"
The Doctor's figure appeared down the hallway as he sprinted towards her.
"You've found it?" he called. "Fantastic!"
But the Doctor's voice had changed again, and now he seemed to be speaking with a Northern accent. As he got closer, Clara saw that his appearance had changed again, too. He now had a large nose and ears that stuck out from the side of his head, and his dark hair was now cut close to his scalp.
He approached Clara and smiled like a madman: wide eyes and all teeth. "Is it through here?" he asked, pointing.
Clara stared at his new (or rather, old) face with confusion. "You've changed again."
"Well don't seem so disappointed about it," the Doctor said. He pushed past Clara and entered the laboratory.
The Doctor went straight for the machine by the table and started scanning it with his screwdriver.
"I don't know why," the Doctor said, "but this version of the sonic feels off in these hands."
Clara was about to say something, but the Doctor cut her off when he held up his screwdriver and viewed the results of the scan.
"Oh, that's brilliant," the Doctor said as he started to pace the room. "That's really, really rather brilliant of her."
"What is it?" Clara asked, approaching the Time Lord. "Doctor?"
"Hm?" The Doctor looked up at her, as if he had just remembered she was there. "Oh right, yes. This machine seems to be an altered version of a chameleon arch."
The Doctor said nothing else, but Clara was still in the dark. "And that is?" she asked.
"It's a Gallifreyan machine used to modify biology," the Doctor explained. "Essentially, it can be used to change the species of whoever uses it. I've used one to temporarily become human once and so has the Master. But the Rani had modified this one so that it can alter regenerations in Time Lord biology."
"So can we use this one to fix you?" Clara asked.
The Doctor sucked in air sharply. "See the thing is, I don't exactly know how this thing works. And I can't exactly trust the Rani to help me."
"So what now?" Clara asked. "You just keep backwards-regenerating until…something happens."
"I've got a chameleon arch on the TARDIS," the Doctor said. He held up his sonic screwdriver and grinned. "And now that I've scanned the Rani's machine, I know exactly how to make one of my own."
"Or, rather, you could get back on that table, and let me finish."
The Doctor and Clara turned to the new speaker and saw the Rani standing in the doorway, a deadly laser rifle in her hands.
"You know I can't let you do that, Rani," the Doctor said, stepping forward. "That kind of power, you'd abuse it."
"The Time Lords never thought to tap into that kind of potential," the Rani stated. "But I did. I'm simply doing this in the name of curiosity."
"Somehow, I don't quit believe that," the Doctor said. He pointed his sonic screwdriver at the altered chameleon arch, and the machine exploded into bright sparks.
"No!" the Rani said, running towards the machine. "What have you done?"
The Doctor pushed the Rani into the table. "Run!" he yelled at Clara.
He grabbed his companion's hand and dragged her down the hallway. Their heels clicked loudly against the metal floors. After a moment, lasers started coming from behind them and narrowly avoiding their faces before exploding into the walls around them.
The duo made it to the console room and dashed for the door. Clara exited before the Doctor, and before he closed the door to the TARDIS, he aimed his screwdriver at the console, causing the time machine to start to materialize.
The Doctor caught a glimpse of the Rani's surprised, angry face as he closed the door and let the TARDIS blink out of time.
"Where did you send her, Doctor?" Clara asked.
"I don't quite know," the Doctor said with a shrug. "But it'll take her a while to find us."
The Doctor opened the door to his own TARDIS and he and Clara entered.
Just as the door closed, the Doctor's body began to glow with golden regenerative energy again.
The Doctor looked at his glowing hands with annoyance. "Really? Right now?"
The Time Lord exploded in a short, bright burst, and emerge with a new face again. This one Clara also recognized; it was the third Doctor from the adventure with the three Doctors. This one looked older than the incarnation she was used to, with a grey beard and his face mapped with wrinkles. His hair was styled with a small tuft in the front, much like the incarnation of the Doctor Clara found cute.
As the Doctor felt his face, Clara cracked a smile. "You're Captain Grumpy now."
The Doctor gave her a furrow-browed look. "'Captain Grumpy?' Is that what I seriously called myself?"
He shrugged. "Oh no matter. We must be off."
He clicked a few buttons on the console and pulled a lever. The TARDIS groaned and the center column rose and fell.
"Where are we going?" Clara asked.
"To find the first component we need for modifying the chameleon arch," the Doctor answered. "I don't have any of the necessary pieces I need on the TARDIS, so we'll need to…borrow them from different sources."
"And by 'borrow' you mean 'steal,'" Clara said.
The Doctor grinned, sending smile-wrinkles to curve around his mouth. The TARDIS stopped materializing, and the Doctor turned to the door.
"Here we are," the Doctor said. "Let's make this quick."
He opened the door, and he and Clara stepped out into a shining hallway, flashing red lights lighting the area. A buzzing alarm echoed down the halls, and what sounded like muffled explosions rocked the walls.
"Where are we now?" Clara asked.
"On a 34th century spaceship in the Meldaan system," the Doctor said. "And it appears to be under attack."
"So make it quick, like you said," Clara said.
The Doctor nodded. "We'll need to find the maintenance room. Let's go."
The Doctor and Clara ran down the hallway, hand-in-hand, as the Time Lord darted his eyes from door to door, looking for the maintenance room.
Eventually, he stopped in his tracks. "This one."
He pointed his sonic screwdriver at the door and is slid open. Instead of the cramp maintenance room Clara expected, the inside was a large room where people dressed in military fashion sat at various stations, pressing buttons and yelling orders frantically. At the front wall was a large viewing screen, on which could be seen a fleet of saucer-like ships open-firing on the spaceship.
Many of the crewmembers turned to look at the Doctor and Clara, and whom Clara assumed was the captain stood up and bellowed at them, "Who the hell are you?"
"Sorry," the Doctor said. "Wrong room."
"Sir!" one of the crewmembers yelled as he looked at a console screen. "Incoming projectile."
The captain locked his eyes on the viewing screen. "Brace for impact! Shields at one hundred percent!"
A torpedo-like projectile rocketed from the lead saucer ship and headed straight for the ship. It looked like it was about to collide directly with the viewing screen.
"Oh dear," the Doctor said, pulling out his screwdriver and aiming it at the doorway. The door slid closed and the Doctor grabbed Clara and pulled her down the hallway.
Suddenly, there was a bright burst of light as the door to the bridge exploded, taking part of the wall with it. The Doctor dove onto the floor and covered Clara with his body as the shrapnel from the door flew over their heads.