Irene Adler was a prominent American adventuress, thief, and love interest of Sherlock Holmes. She was Holmes' adversary on numerous occasions, even working for his nemesis Professor James Moriarty, who murdered her in 1891 when he no longer needed her assistance.

Who killed Irene Adler?

Jamie Moriarty, initially known to Sherlock as Irene Adler, is a criminal mastermind and the nemesis of Sherlock Holmes. Moriarty is at first thought to be directly responsible for the death of Holmes' lover, Irene Adler. Moriarty is also responsible for 70 murders over her career.

Is Irene Adler actually dead?

She is presumed dead, with the only information on her given by Mycroft Holmes, mentioning that she was captured by a terror cell and beheaded. A flash back at the end of the episode shows that when she was about to be executed by the terrorist, she sent a goodbye text message to Sherlock.