Because there were two of them. Two. Always two, rotating binary stars, circling each other for all eternity, never leaving. Complementing each other, bouncing back and forth, back and forth across the eternal night, orbiting the other as a lifeline, the only connection to a dead race.

The Doctor and the Master.

He was the Moriarty to his Holmes, in more ways than one, as they realize. End of the universe. Have fun. Bye-bye! and Allons-y, Alonzo and popping in and out, the same eternal cycle. Until the game changes, and they hide, and somehow because they are always they, one and the other, together, the same absolute value, the only difference in presentation and predilection and charge. Somehow they are in the same space, occupying the same coordinates.

And sparks fly.

The clash of the titans, ever eternal, but mixed up and confused and juggled, because the Master no longer has the eternal drums and the Doctor has lost everything.

Because the Doctor has a love for the dramatic and the Master has finally learned about clichés.

Because Sherlock and Jim are linear pairs, add up to a hundred and eighty degrees, fit each other.

Because Jim and Sherlock each have mysterious fob watches.

Because the Master no longer feels the urge to destroy but the Doctor has lost River and Amy and Rory and no longer feels the urge to care.

Because Moriarty hired Irene because she reminded him of someone who he couldn't know and Sherlock has a hypnotizing affect on those he wants to impress.

Because Sherlock hates percussion and Jim hates pears.

And golden light spills out of the fob watches, and Sherlock and Jim meet again, and they stare at each other for the longest time, until John demands to know what is going on and they, because they are always a they, repel each other and run away, always running.

And the newspapers say that Moriarty is dead, and his organization with him, captured, Sherlock rubs his face tiredly and goes to find out what the Doctor has done to himself now, when he realizes what his human persona has done.

Just a little theory of mine, speculating on the behaviors of Sherlock and Moriarty and the correlation to the Master and the Doctor, and who might fit who. (ha, I made a pun!)

I haven't actually seen any Sherlock past 2x1, (season 2, episode 1) so this is just based off what we've seen of them.

Enjoy, review, fantasize about Cumberbatch!Master. Have a cookie.