Casting 1.3 - The great game

This episode doesn't lack of excellent characters ! I made a subjective choice with the list below :

Casting 1.1 A study in pink

In this introductive episode, all main characters are present (aside Mary Morstan and Bill Wiggins, season 3). Below are the characters appearing only (or mainly) in this episode.

1.2 - The blind banker

Sherlock is called by an old acquaintance. An intruder came in a high secured bank and painted a mysterious sign on a painting. The bank wants to know how he did it. 
Soon after, the trader working in the office where the intrusion occured, commits "suicide". Or so it seems... He was coming back from a trip in China.

1.3 - The great game

Mycroft ask for his brother's help (sort of) in dealing with an affair of national interest.
While Sherlock affects to refuse, a bomb explodes in Baker street. That's the beginning of a game which will lead to a crucial meeting between Sherlock and his biggest fan...

Casting 1.2 - the blind banker

1.1 - A study in pink

John Watson is a veteran from Afghanistan. He came back to London with a wounded leg, but that's the normality of daily life he can hardly cope with, until he meets a "freak", Sherlock Holmes, with whom he soon shares a flat. Besides, his new friend gets him mixed up in an investigation about serial suicides.

What a good surprise !