‘Sherlock’ season 4: Exec on big Euros Holmes casting secret

To say that Sunday’s episode of “Sherlock” was shocking would be making one of the biggest understatements of all time. (Warning: Spoilers ahead.)

Remember the third Holmes sibling rumor? This is something that we’ve heard about for years now, but on “The Lying Detective,” such a theory became reality as we met for the first time Euros Holmes. The twist here was that Euros was Sherlock and Mycroft’s sister, and there were certainly some ties between her and other characters within the mythology.

Given that almost nothing was revealed about this character or Siân Brooke’s casting in advance, the producers had a tough task trying to keep her a secret for so many months. Speaking (per the Radio Times) while at a Bafta event earlier today, executive producer Sue Vertue had the following to say all about it:

“I think some of [the biggest difficulties] were trying to keep Siân under wraps … Where she was seen in public, where she wasn’t seen in public, and [which character she was playing].”

Meanwhile, fellow EP Steven Moffat said that “if it hadn’t worked, there wasn’t an awful lot we could do about it … We were careful in the shots, in what you saw and all of that.”

Maybe the producers of this show took some cues from some other shows notorious for keeping secrets, whether it be “Game of Thrones” or another one from Moffat in “Doctor Who.” Luckily, the producers pulled this off, and in the process gave many of their viewers something significant to talk about over the course of the next several days. We’ve got almost seven of them to go now between now and when the finale airs, and while that may feel long, remember this — it’s definitely a heck of a lot easier of a wait than what we had in terms of season 3 and season 4 — and whatever the wait could be between a season 4 and 5, provided that the latter even happens in the first place. (Wouldn’t it be hilarious if there was a fourth sibling out there? We’re joking — kind of.)

Are you still reeling from the Euros Holmes shocker, or did you actually see this coming? Let us know in the comments, and head over here to get our full review for “The Lying Detective.” (Photo: BBC One.)