"The Case-Book of Sherlock Holmes" The Master Blackmailer (1992) [TV] TMDB Douban
"The Case-Book of Sherlock Holmes" The Master Blackmailer Season 6 part of TV Series: Sherlock Holmes
This isn't really a season so much as three feature length TV movies that were broadcast from 1991 through 1994, again with the same actors, production company and style as the others that came before.