Sherlock Holmes was the world's only consulting detective.
At least, that's pretty much how he introduced himself.
John Watson didn't seem very convinced until Sherlock, in one sentence, completely unravelled John's entire life after meeting him for a mere 5 minutes.
You have to admit, that is pretty damn impressive!
So, John Watson became Sherlock's new flatmate and, quicker than you could say "there's a head in the fridge", John was Sherlock's sidekick: visiting crime scenes, analysing data and shooting psychopath cabbies-with-a-death-wish.
John Watson was the Yin to Sherlock's Yang.
Where Sherlock was single-minded, erratic and wild: a whirlwind in a meadow; a powerful but tactless mind, John was grounded, calm and thoughtful: a listener; a tether for Sherlock's wayward kite; an anchor for his listing ship; a heart.
Before long, Sherlock was wondering how he had managed to exist before John. Was there life before John? Sherlock could barely remember.
John made Sherlock whole. John made Sherlock... good.
Everybody assumed they were a couple.
It was an obvious conclusion, Sherlock thought. They clearly had some sort of connection.
Sherlock was dark, John was his light.
Sherlock was wild, and John tamed him.
Sherlock was 'not good', and John put him right.
There was little that John would not do for Sherlock and vice versa.
Brains; heart; love; light.
They were unstoppable.