As he started to black out due to the blood flow to his brain getting squeezed, Pollux's last thought was that Castor certainly didn't learn that move at the Taekwondo class...
"Enervate."
Pollux woke up to find himself tied to a chair, and facing Castor. Castor's wand was in his hand, held with the deceptive looseness of the hyper-alert.
"So you didn't kill me." Pollux observed.
"I already said I was just there to watch, Pollux." chided Castor. "Why did you call me Tom?"
Pollux didn't reply. He wasn't in the mood for another interrogation today.
But of course that was not about to stop Castor... "No answers? Let's move on to something else then... what did Dumbledore want with you?"
"He wanted to know why there is a child with the memories of Tom Riddle in his school."
"How did he... oh yeah, the Hat of course."
Pollux was surprised that Castor guessed correctly immediately. Did everyone know it apart from him? Wait... it was looking more apparent that Castor was in no way Tom Riddle. But what if he was someone else? Someone who know the secret of the Sorting Hat. Someone... like Albus Dumbledore.
He didn't voice his guess. He wasn't about to risk the embarrassment of another wrong guess in front of Castor.
"So Dumbledore told the hat to watch out for little pieces of Tom Riddle, and the Hat got you because you have all of his memories. Huh. I bet he scared out the entire truth of why you are really here, judging by how shaky you looked when you came out of his office."
He must have been really shaky if he hadn't noticed an observer, Pollux thought.
"Now Dumbledore knows everything, and he... just let you go?" Castor speculated.
"He tried to memory charm me."
"Ah. Hmm. Yes, that makes sense. That would actually have been a good plan - if it had worked. Every time he finds something new, bam - he calls you into his office under some pretext, repeats the whole scary routine and confirms all of his guesses, then obliviates you and send you back. Meanwhile, you - unaware that Dumbledore is on to you - carry out whatever plot you have without undue paranoia. Hey. Trust Albus to come up with the most ruthless method of giving mercy to his enemies!" Castor sounded quite admiring of Dumbledore.
Pollux was miffed. His anger got the better of his control and he said "Well Dumbledore does not know about the other Voldemort roaming Albania as a disembodied..." Pollux stopped. How was he able to tell everything to Castor.
Castor seemed to have interpreted his confusion correctly "I already know all this Pollux, but in any case... I am a special exception to your little Non-Disclosure Disagreement. As you are to mine."
"And what secrets do you have?" asked Pollux.
(Somewhere between life and death: Sometime in the past... or in the future)
"I suppose I will have to make new mistakes", grumbled Tom. "I'd like to get on with it then, if you don't mind."
"Of course I don't mind, Tom... if you would just step through this door here..."
When Dumbledore returned to room there was another figure standing there. "What do you think?", he asked the figure.
"I don't trust him one bit. He needs to be watched"
"Well of course he needs to watched, old friend" Dumbledore countered in quite a jolly fashion. "Why do you think I have you?"
"What do mean?" asked the figure, stepping into the light and revealing himself to be another old man - about as old as Albus Dumbledore himself. But whereas Albus Dumbledore had the general geniality of a lovable grandfather, this man had a grizzled, scarred appearance and a demeanor of cold fury. Whereas Dumbledore brought to mind a picture of a sheathed sword, he was a naked blade pointed right at you.
"He's not going to be alone." Replied Dumbledore. "He'll have one of us to watch him at every step."
"One of us?" repeated the other man with an air of false and temporary calmness.
"Well... you actually." said Dumbledore, a bit abashed. "You will be the man on the inside, keeping an eye on him till he succeeds in his quest."
"Or fails" countered the other man. "Do you not remember that I already defeated my Dark Lord? I didn't have to do it, but I did it alright! Then I defeated a whole bunch of other aspiring Dark Lords for thirty years, and then legislated the hell out of even more for another thirty. All I wanted to do now, was to meet my wife in the afterlife and spend the rest of eternity with my family."
"Oh, I know you better than that." said Dumbledore. "Did you not keep taking the most perilous missions when your wife and children were waiting for you at home? When you were alive? You would have gotten bored of any idyllic eternity within minutes. I just saved you a bit of boredom, old chap."
(Now)
"Oh, I have a few." Replied Castor. "Just like you have your mission, I have mine too."
"Funny you should say that" quipped Pollux quite wryly. "I have no idea what I'm supposed to do. I do hope your instructions are a bit clearer than mine."
"They're clear enough." said Castor. "I keep an eye on you, and help you when you need me."
"Oh yes, I can see you are very helpful in tying me up."
Castor glared at him. He withdrew a huge knife from his ankle and approached Pollux holding the knife. He came uncomfortably near and pointed the knife at Pollux.
"Why did you call me Tom, when you knew very well YOU were Tom Riddle?" he asked.
Pollux figured out refusing to answer was not an option this time. "It was your behaviour." he said, "right when you killed that snake and disposed of it like a professional assassin. I've been watching you since - you were always cold and detached. All the emotions on your face... they never reach your eyes. Sounds familiar?"
"So I was a creepy kid. Why specifically that creepy kid?"
"We were twins, and we were named after the Gemini - the twin constellations. Are you familiar with the Pagan myth of the Gemini? Castor dies, and Pollux asks for Zeus to share his own soul with him so that Castor may live again - thus binding himself to the other for eternity. But it costs him his immortality, and he has to split his time between Olympus and Hades.
"Given my own experience in splitting my soul, and the bargain I made to surrender my immortality, I thought it was a reasonable guess that you had another part of my soul. And like the Pollux of mythology, it was my fate to save you."
"Huh." said Castor "that does make a certain kind of sense. If you were a superstitious old man that is."
Before Pollux could express his irritation, Castor continued "you are not powerful enough to afford to be superstitious. Actually your theory can be made to fit the facts of my life, but you still have the wrong end of the stick. Now that you've twigged I was never Tom Riddle, do you want to guess who I am?"
Pollux hesitated, then answered "If you are not me then you are a counterpart of me - you are me from another direction, possibly my chief nemesis. You are Albus Dumbledore."
Castor looked at him strangely, and said "I don't know whether to be amused or outright insulted by that. Now you are holding the wrong stick entirely.
"Aren't you forgetting another wizard, who could be a counterpart of you? A wizard a lot like you, and more closely bound to you than any two wizards in all of magical history?"
(Somewhere between life and death)
"THAT WAS NOT YOUR CALL TO MAKE, ALBUS!" the grizzled old man raged at Dumbledore. "I want no part of your mission. If you want to keep an eye on the bastard, do it yourself!"
"It will be but a blink of an eye to you, old friend." Albus tried to mollify his friend. "Eternity is hardly running away. Your family will still be waiting for you when you finish this and come back."
"You're talking as if I have agreed to this. I have not. Are you listening?"
"Don't you think you are being a bit irresponsible here? It was due to you that Tom was able to start his journey to redemption..."
"Not on purpose. And what are you saying, if I save someone I'm responsible for them? Like that Chinese proverb?"
Albus Dumbledore sighed, "Alas, it seems you won't change your attitude-"
"Damn right I won't" interrupted the other man.
"... so I will have to make other arrangements to watch over our young redeemer here." finished Albus.
"Who will you send, Albus?" the other asked, unable to contain his curiosity despite himself.
"Well... you. The alternate arrangement merely consists of sending you unwilling. Goodbye, for now, old friend"
(Sometime in 1983)
The old man woke up to find himself as a three, almost four year old Castor Black.
"ALBUS YOU GOAT SUCKING TURD MUNCHING DICKWAD!"
Castor Black had his mouth washed with soap by Andromeda Tonks (nee Black).
(Now)
Castor used the knife to cut off the ropes binding Pollux. He gave his wand back and extended his hand for the other boy to shake.
"Pollux Black - also known as Tom Riddle, I hope we will get along better in the future. I'm Castor Black; also known as Harry Potter."
Author's note: Phew, finally that revelation was done. Congratulations, Purple Marshmallows, you win, for guessing correctly that Castor Black was Harry Potter!
My original draft had Castor telling it to Pollux as soon as he enervates him after the fight, but because of how I ended the previous chapter, that revelation would have come right at the beginning of the chapter. Then the chapter would be filled with boring stuff. Not a good way to structure. So I had to rearrange the narrative so that the revelation comes at the end.
I had originally just hand-waved that the Gemini twins had some mystical significance, but for the life of me I didn't know what I'll write when the time came to explain it. I got lucky - when I checked in Wikipedia, I could see a way of bending the legend to fit my story.
I'm running out of story now. I have another chapter lined up where Castor and Pollux just talk to tie up loose ends, but this is the end of the original outline I'd written up. I have parts from the Tri-wizard sequence planned, but no plan of how to get there. So do expect future chapters to be delayed some while I plot.
And finally, in the finest traditions of another story in which unwilling powerful men are shanghaied into world-saving missions, here's the part that comes after the credits.
(Somewhere... else)
Albus Dumbledore sighed. His eyes were shining, but not the twinkling he's always known for. This time they were unshed tears.
"I'm so sorry, Harry."
