"Geronimo, old man."

"Hey," the Doctor growled, stone-cold serious as he pointed his mop at the Child of Storms. "That's my line."

The Time Lord lunged at his adversary, his brilliant fencing in direct contrast to his eccentric style of dress. For a few moments, as sword of dwarf-star iron and mop of two-bit wood clashed, it seemed that the Doctor might win. Then he found an opening, and his sneer of triumph was dwarfed only by his wail of dismay as his mop thwapped harmlessly against the night-black armor. In reply, the Child of Storms swung his sword and sheared the mop clean in two.

"You've lost, Doctor."

"Well, no, not lost as such, not yet." With a little laugh, the Doctor pressed a hidden button in the mop handle. There was a brief moment of tension in the space-time continuum as a paradox took hold, and then the mop was whole again.

"I can do this all day, Alfie," the Doctor laughed. "I can call you Alfie, can't I?"

"Nobody can really tell you what to call anybody, Doctor," the armored monster growled through his helmet, "though I prefer to be addressed as Stormageddon, Dark Lord of All."

"Really, Alfie?" The Doctor snickered as the low rumble died away. "If you're still using that childish title, you may as well go back to calling me Also-Not-Mum."

The TARDIS echoed with the boom of slamming coffins that was Stormageddon's laughter. For a moment, the shiny metal walls seemed to crack and break.

"Oh, that's rich. Very well, Also-Not-Mum. Have at thee!" The Dark Lord of All raised his sword and took up a classic fighting stance.

"Have at me?" The Doctor had on an expression of ridiculously injured pride. "Have you really become so cheeky that you think you can just have at me and win?" Reaching into his jacket pocket, the Doctor produced a fez and put it on his head with all the ceremony of a king donning his crown.

The Doctor hurled himself at his enemy, twirling and leaping like a demented ballerina. Impassive as ever, the Child of Storms gave a lazy swipe of his blade. When it connected with the mop, the wooden shaft exploded into swirling dust. As the grains fell between his fingers, a mad giggle burst out of the Doctor.

That's new."

"Actually, atomization at the instant of contact is a fairly outdated concept in my era." Stormageddon pressed a button on his sword hilt and the blade split down the middle. In the tiny gap at the center was the red glare of a laser.

"This, though, is cutting-edge." It was impossible for any expression to be seen through the obsidian-black helmet, but the Dark Lord's mocking tone conjured up the image of a greasy sneer. He pointed the sword at the Doctor, so that the laser shined its light directly on the Time Lord's confused face.

"I have lived long and travelled far, Also-Not-Mum. I have searched the stars for you, and have found only the unknown. I discovered what desperately wanted to stay hidden. I have learned everything there is to know about space, but space has learned barely anything about me. I am NASA's greatest asset, the Astronaut who Does the Impossible. In recent years, I have come to be known as space's worst nightmare. There is not a single alien out there who won't scream in terror when someone mentions my name. I am the single most terrifying thing in all of time and space, and nobody knows it better than my father."

As Stormageddon rambled on, the laser grew brighter. The Doctor felt enormous pain in every cell of his body, almost as if...

No. It couldn't be.

"But compared to you, I have lived hardly any time at all." Another bone-chilling laugh boomed through the control room, and the Cloister Bells rang out. "You are so old. Oh, you seem young and vibrant, but you are old. And now, faced with youth, you tremble and yelp like a whipped animal."

A weak whine escaped the Doctor's mouth as the pain doubled. No doubt about it now, he knew what was happening. Time, his own personal time stream, was being rewritten. He could hear, he could feel, the TARDIS screaming as it tried to cope with what was happening.

"Such a long life," Stormageddon mused, as though oblivious to the sounds of illogical anguish. "How many years do you have left, Doctor? Not enough, I think. Why not adjust that number a little?"

Then something happened. Time splintered between Stormageddon and the Doctor, opening a rift through which energies unknown even to the Face of Boe seeped into reality. The Doctor felt raw time pouring into him, felt his own DNA rewrite. It was an experience even more painful than regeneration, and for a moment the Doctor remembered the Master's laser screwdriver. But surely Stormageddon could not...

The splinter healed. Either thanks to the pressures of reality on all sides, or by choice of the Child of Storms, the flood of days and months and years was halted. The Doctor looked up at Stormageddon, and felt that he was more tall and imposing than he had ever been. Too tall, the Doctor thought. Then he realized what was wrong, just as the fez slipped over his eyes.

"How does it feel to be young, Doctor?" Stormageddon was clearly mocking him now, a low rumble echoing around inside the black helmet. "How does it feel to be like me?"

The Dark Lord of All reached up a metal hand to his helmet and pulled it off. The blank face of dwarf-star iron fell to the floor with a crash, and the Doctor gasped.

"What have you done, Alfie?"

"I have made myself better," the evil one replied. He smiled at the Doctor, who just stared back as he raised his fez. For there, framed by an ebony-black collar, was the innocent chuckling face of a baby.

"You call this better? I can see what you've done here, Alfie, and it is unforgivable."

I see it as an improvement. It took years for me to become the man I am. How much better could I be if I had started from infancy? So I travelled back in time to the days of my childhood. It was the work of a moment to transfer all of my memories and personality into my past self. And so, that version became the true Stormageddon. I then fitted myself into this indestructible exoskeleton so that I might walk and talk in the manner of men." While the Dark Lord of All monologued in his voice of conquerors, his baby face gurgled and giggled a completely different tune.

"What happened to the original?" the child Doctor asked. "The Stormageddon who travelled back in time, what happened to him?"

"I had no further use for that body," Stormageddon said dismissively. "I disposed of it."

The child in the fez shook his head as he got to his feet. "That's not what happened, Alfie. Don't you understand what you've done? By going back and changing your own past, you removed yourself from time. All those memories you have, of being NASA's space ace, of tearing apart the stars, none of that happened. All those adventures were erased from existence the moment you put a baby in a suit of armor. I bet you thought you were just stepping from body to body, like a Time Lord regenerating. But you have fallen short of Gallifrey's glory, Alfie Owens. Tell me, why did you search the stars for me?"

"I wanted to join you in the TARDIS, Also-Not-Mum. I had all of space, but not enough time to see it all."

The Doctor swaggered up to the titan and pointed an accusing finger at the baby. "So why did you try to kill me the moment you got in here?"

The gauntlet of alien iron grabbed the Doctor by his collar and hoisted him up into the air. "I have come here to steal immortality, Time Lord. And your death is all I require."

"I knew it," the Doctor laughed. "That transfer made you lose your mind. Everything about you has gone completely... wait what was that?" Before he could process what he had heard, the Doctor was hurled into the wall of the TARDIS. As he fell to the ground, he felt his ribs crack and shift. The unmistakable sensation of his lungs being choked caught his attention.

The conqueror advanced, crushing the fez under his metal foot and gloating over his fallen foe. "Regeneration, old boy. The key to countless lifetimes, the Holy Grail of genetic perfection, immortality wrapped in a triple-helix of DNA. That is what I came here for. You have been physically regressed to childhood, with all your regenerations undone and waiting to happen."

With a wide grin, Stormageddon pressed a button, and his weapon changed again. The two sections of the blade reconnected and a new ray of light gleamed along the edge. The Doctor tried to cough, but his body wisely preserved the breath.

"You are dying, ΘΣ. Soon, even your formidable lungs will be unable to hold the oxygen you require. Your own body will be your end, choking you and denying you breath. But before that can happen, I will have the personal pleasure of spilling your guts on the floor of this flying hunk of junk."

The weak and helpless child on the floor, who had once made entire armies turn and run at the mention of his name, could hold in his breath no longer. "What is that supposed to accomplish?" he gasped. "I'll just regenerate."

"Wrong, Time Lord. Once the regeneration begins, I will drain every atom of that life-restoring energy. You will be dead, and all of your regenerations will be poured into my heart. But they will not remain regenerations, Also-Not-Mum. All that energy will serve to enhance my DNA. I will be immortal, Doctor. No child before has ever received such a gift."

"That is, unless I do this." With a greasy sneer, the Doctor reached inside himself and accessed the dormant energy within his cells. The Dark Lord of All watched, laughing as the golden mists of regeneration poured out of the child's skin.

"Forcing the regeneration will not help you, Doctor." He twisted his sword hilt, and it sprang apart yet again. Lightning crackled between the two prongs of the weapon. "As long as you die, I can still drain every single generation from your body."

A bolt of lightning shot out at the Doctor, crackling across his broken body. For a moment, his face contorted into an expression of unbearable pain. Then it was replaced by a blissful smile, and the energy withdrew into the sword. The blade snapped shut, and Stormageddon stared at a holographic readout.

"That's impossible!" he roared. "How could you withhold that energy from me? I saw you dying!"

"What you saw," the child laughed as he sat up and breathed happily, "was the use of regenerative energy to heal an injury without the need for full rebirth. In most cases it's a complete waste of energy, but your little trick left me with two full tanks. Literally, I could regenerate almost 26 times now."

"Shut up." Stormageddon raised the sword over his head, gibbering madly in Baby. "I'll just cut your head off. I'd like to see you heal that."

He swung the sword in a low, sweeping arc that sliced its way down toward the Doctor. In the split few seconds before his demise, the Doctor pulled his sonic screwdriver from inside his jacket, aimed and clicked. A pocket of steam erupted from the collar of Stormageddon's armor, blinding him and giving rise to a high-pitched wail. But blindness did not matter to the Dark Lord of All, and his blade continued its fall until it made contact. There was the sound of metal splitting, of the TARDIS screaming, but not of flesh tearing. The smoke cleared, and Stormageddon roared in anger. His blade had torn a great scar in the impossible metal of the TARDIS, but there was not a single stain of Gallifreyan blood. Turning on his metal heels to face the control console, the Dark Lord saw the Time Lord.

"You always overlook these things, Alfie." The Doctor laughed and tossed his sonic screwdriver up in the air. "Now, how's about we get you back home?" Without waiting for an answer, he began to turn knobs and pull levers as he raced around the console.

"What are you doing?" Stormageddon demanded.

"Taking us back to your time!" The Doctor laughed and pulled a lever, causing the TARDIS to buck and tumble through the vortex. "If I can take us back, get you out of that suit, and leave you gurgling in the crib like a normal baby, then everything will, hopefully, go back to normal. For you, for your mum and dad, and maybe even for me!"

The armored monster stumbled and screamed as the time machine travelled on. The Doctor whooped and laughed, enjoying himself immensely as the Child of Storms was sent sprawling on his stomach. The helmet that had earlier been the face of terror now bounced around the TARDIS like a rubber ball. Stormageddon finally got back to his feet when the TARDIS spun around, narrowly missing a collision with New Earth. The Dark Lord of All growled, and pointed his sword at the control system. He pressed a button on the hilt, and a very familiar sound filled the room. Sparks flew, and they jumped a time track.

"Was that a sonic sword?" the Doctor asked as he got up from the floor.

Stormageddon shrugged and sheathed the sword. His face appeared to be embarrassed, though it was hard to tell with babies. "No." Then his helmet bounced into his hands, and the Dark Lord of All hid his face from the Doctor.

Chuckling to himself, the young Time Lord did a handstand on the controls, still turning knobs and pulling levers. Finally, he spun the hot and cold taps and fell on his feet. "Right, then. Come with me, Stormageddon. I've brought you home, and I'd like to get you out of those clothes before your parents wake up." He trotted out the door, whistling a jolly little tune while Stormageddon lagged behind, casting one last glance around the control room of the TARDIS. Then he heard the Doctor shouting, and strode out into a place that was definitely not his bedroom.

"How is this possible?" The Doctor was turning around in circles, scanning with his screwdriver. "The TARDIS said this was your room, but it's not! It's..."

"A pocket universe," Stormageddon sneered. "It's a spare room that doesn't fit anywhere, therefore it exists here." He ran an armored hand over the wall, as though the cracked and paintless gyproc was the most beautiful thing in all of reality. "I discovered this when I was playing with a vortex manipulator I liberated from the Time Agency. It had been damaged, and my attempts to come home for Christmas were delayed by an adventure in this lovely place."

"How could you have an adventure in a dimensionally-displaced bedroom?", the Doctor demanded. "It's not as if there's anyone else here! And that door..." The child threw himself at the blank walls as though he expected them to be made of paper. "Where did that door go?"

"There wouldn't be any point in having a door that didn't go anywhere, Doctor. And for the answer to your question, let me pose another. What's that you see on the bed?"

The little boy had been hoping that he wouldn't have to look. But now he turned, and saw what he was missing. For there, on the rickety, torn, moth-eaten bed, was a teddy bear. And when the Doctor focused on that teddy bear for even a moment, every fear he had ever had hit him in the back of the head. He spun around, terrified and wanting to throw himself into the safety of his box. But there was nothing there.

"What have you done with the TARDIS?" he demanded. In answer, Stormageddon kneeled and picked up what seemed a lot like a toy TARDIS.

"This is what the bedroom does," he explained. "The bedroom can't fit anywhere. Your TARDIS, on the other hand, can fit in everywhere. So the bedroom got jealous. It amplified the radical differences between the inner and outer dimensions of your vehicle."

"Your nomadic bedroom shrunk my TARDIS." The child looked up at the faceless knight, tears of resignation in his eyes. "And now what? You cut me open and steal my regenerations?"

Stormageddon laughed, tossing the little blue box at his adversary and walking over to the bed, where he picked up the teddy bear. The Doctor fell to his knees in silent pleading as the Dark Lord of All walked back across the room.

"A child's bedroom is the scariest place in the universe, Doctor. But how much more scary, when the embodiment of pantophobia lies by your side?" He dropped the teddy bear, and chuckled as the boy cringed away from it.

"But..." he stammered, "I'm not afraid of pants."

"Oh, you will be. You'll be afraid of shirts, too. And socks, and trousers, and bowties. You'll want to get rid of them, except you'll be afraid of nudity too. You'll be afraid of everything. There won't be a thing in your past that you won't look back on with terror. Nothing." Stormageddon stepped back, and pressed a series of buttons on the sleeve of his armor. Then he assumed the pose of a guarding knight, and his armor locked up.

"It will be so much more satisfying," his voice echoed out of the immobile metal shell, "to wrest immortality from the hands of a starving old man who has spent his life too scared to even blink." The Doctor winced, and the laughter came again. "Oh yes, the blinking. That should be fun to watch later. See you in a few centuries, Doctor. It's times like these that a man enjoys making an investment in portable cryogenic suspension."

There was a sinister hiss of air within the suit, and a slight membrane of frost formed on the impenetrable iron. The Doctor just sat there, cradling his box in his arms. Every once in awhile, his eyes would dart to the teddy bear, but only for the briefest of moments. Spasms of terror shook his frail body, and eventually he began to mutter. If anyone had been listening, they would have heard the names of every enemy ever to duel with the Doctor. They had all been defeated before, but no longer. For now, in this place, in this time, the Doctor had lost.