@piyushrocks
Just a additional note to what User 4869 said, if the Black Organization Plot Legend is on the plot column in the Anime page on the wiki, that means the Black Organization makes an appearance in the episode the plot legend is in.
Thought this belonged here, if not, please do let know know the appropriate place to post questions such as the following.
Gin > Quotes > "So long... great detective."
Where is that quote from?