There’s a convincing “Sherlock” theory about vampires, and nothing surprises us anymore

We don’t know about you, but we’re still reeling from the end of Sherlock season four episode two, “The Lying Detective.” Obviously there are spoilers ahead, because COME ON. 

At the very end of the episode, we learn that the mysterious women who’ve been popping up in Sherlock and John’s lives (E, the woman John’s been texting, and the woman who claimed to be Culverton’s daughter at Sherlock’s apartment) were actually the same person and she was also posing as John’s new therapist!! In the final seconds of the episode, she reveals herself to be Euros, the long-lost third sibling of Sherlock and Mycroft. GASP, indeed.

Naturally there are countless fan theories swirling around the internet as to why Euros is back and what she has in store for our beloved Sherlock characters. The latest theory swirling around Reddit is about vampires (crazy, right?) but actually sounds like it could be plausible.

According to a post by Reddit user Dannny8987, when E was texting John and she claims to be a vampire (because she’s up so late at night), it’s actually a hidden reference to an Arthur Conan Doyle story, “The Adventure of the Sussex Vampire.”

Here’s Dannny8987’s full theory…

“In Doyle's story 'The Adventure of the Sussex Vampire' the eldest sibling tries to kill his baby half-brother, and practices on the family dog beforehand. I think either this is exactly what happened to Readbeard (killed by Euros rehearsing her plan before turning on Sherlock) or that Readbeard saved Sherlock from his sister's assassination attempt and got accidentally killed."

Hold up. You remember Redbeard the dog, don’t you? He’s Sherlock’s pressure point, and we started seeing him pop in and out of Season 3. This last episode of Sherlock also showed us flashbacks of the dog, and suddenly, this theory sounds semi-plausiable.

"Also I don't think they thought she was dead, otherwise they (and Mycroft in particular) wouldn't reference at her (well, at the "east wind" and "the other one") so often," Dannny8987 continues. "But certainly Mycroft thought he had the situation under control, and that she was no longer a threat. That she'd been ‘dealt with’.

Based on how Mark Gatiss and Steven Moffat have previously incorporated Doyle stories into their own Sherlock Holmes narratives, we can definitely see how this theory works. While it’s a pretty crazy theory, this is Sherlock. Nothing is out of bounds.

We’re definitely going to have to rewatch “The Six Thatchers” and “The Lying Detective” to see what we missed and we’ll definitely be testing this theory next week in “The Final Problem.”