Martin Freeman and Amanda Abbington
Martin Freeman and Amanda Abbington Reuters

Amanda Abbington, who joined the cast of "Sherlock" season three in the role of Mary Morstan, revealed she had to face the wrath of the series' diehard fans.

Abbington, who play's John Watson's wife in the detective series, faced death threats from some extreme fans over her role.

"When I told everybody I was playing Mary, there was a small group who wanted me dead. I got, 'She should die. How dare she play Mary Morstan? How dare she!'" the actress told The Times.

Abbington said that the fans' obsession with lead actors Benedict Cumberbatch and Martin Freeman's impressive camaraderie is palpable. "They take the John and Sherlock storyline so seriously that they wouldn't want anyone coming between them," but clarified that a romance between the two characters is unlikely since "it's like a brotherly love."

Interestingly, Abbington is the real life partner of Freeman, who plays Sherlock Holmes' sidekick Watson. They have been together for 11 years and have two children - Joe and Grace.

Meanwhile, "Sherlock" season three is set to conclude with the final episode "His Last Vow" to be aired on 12 January (Sunday) in the UK. And early reviews have stated that a prominent character will be killed in the episode, which will have Holmes facing nemesis Charles Augustus Magnussen.

However, as a solace to the fans, the show's creator and writer Steven Moffat has assured the fourth season of the detective's adventures will return soon.