Sherlock (2010) – Season 4 – Episode 2 – The Lying Detective – Sherlock’s Sister Eurus Enola Holmes

Dr. Watson’s therapist turned out to be the secret sister of Sherlock Holmes.

Eurus: I’m Eurus.

Dr. John Watson: Eurus?

Eurus: Silly name, isn’t it? Greek. Means the East Wind. My parents loved silly names. Like Eurus, or Mycroft, or Sherlock.

[sees Watson is baffled]

Eurus: Oh, look at him. Didn’t it ever occur to you, not even once, that Sherlock’s secret brother might just be Sherlock’s secret sister?