Outlander has always excelled at weaving together history, mystery, and wild twists. So it should come as no surprise that fans of the Starz hit show are already speculating as to identity of the “Nuckelavee” who has been haunting Lallybroch in the 1980s. While book readers might have their theories, Outlander Season 7 hasn’t done too much to clue long-time viewers in on what’s going on with the mythic creature Jemmy (Blake Johnston Miller) claims to have seen. So what is a Nuckelavee? Who could the Nuckelavee be? And does this seemingly innocuous storyline somehow spell doom for Brianna (Sophie Skelton) and Roger (Richard Rankin) in the “present day”?

We first learn about the Nuckelavee in Outlander Season 7 Episode 4 “A Most Uncomfortable Woman.” Early in the episode, Jemmy lies about taking apart the family radio, claiming the “pixies” did it. Later, though, he insists that he didn’t steal the biscuits, crisps, or lemonade that’s missing. He says it was the Nuckelavee. Brianna is immediately confused, but Roger recognizes it as a folk tale from the Northern Isles of Scotland. “Kind of a horse-like demon,” Roger says. (Great!) Jemmy adds that he’s met a Nuckelavee, which sounds like a nightmare to be honest.

see also

‘Outlander’ Stars Say You Can Feel “The Ghosts” on the Lallybroch Set

"It's a very special place...feeling the ghosts in that place... By Meghan O'Keefe @megsokay

In this past week’s episode, Outlander Season 7 Episode 5 “Singapore,” the plot thickens. Roger discovers more snack wrappers on the Lallybroch estates and Mandy (Rosa Morris) screams when she sees someone lurking outside the house. She identifies it as the Nuckelavee, but Roger thinks it might be whoever is littering on their property. Roger attempts to find the culprit, but comes up short. However the scene is shot in such a way to suggest that there is someone hiding in the woods outside their house.

Who could it be? Is it the Nuckelavee? And why do we get the sense from the Outlander Season 7 Episode 6 trailer that we might learn who this peeping Tom is next episode? (Could it be the harried way Roger runs out the door at Lallybroch at the end of the teaser?)

Here’s everything we know so far about the Nuckelavee on Outlander…

Nuckelavees are a particularly nasty mythic creature in Orcadian (aka deriving from the Orkney Islands) folklore. As Roger explained, they’re basically horse demons, with some 16th century descriptions comparing them to centaurs, albeit two-headed, finned centaurs with toxic breath and no skin. It was thought that the Nuckelavee’s breath would wilt crops and that the creature was responsible for droughts and plagues.

The one mythic creature with the power to bring the Nuckelavee to heel was the Mither o’ the Sea. Legend had it she would battle and confine the Nuckelavee to the depths of the sea each summer.

While it’s clear that Jemmy and Mandy have been seeing someone who is particularly scary, they haven’t necessarily made contact with a two-headed skinless centaur with murder breath. So who could they be seeing? Potential spoilers for Outlander Season 7 and massive book spoilers ahead!

Are you okay with being potentially spoiled? Okay…then you can keep reading…

Folks who have read the Outlander books by Diana Gabaldon probably think they know exactly who the Nuckelavee is: William Buccleigh MacKenzie, aka “Buck MacKenzie.” He is the illegitimate child that Dougal MacKenzie (Graham McTavish) fathered with time traveler Geillis Duncan (Lotte Verbeek). Meaning, he’s technically both Jamie’s (Sam Heughan) cousin and Roger’s direct ancestor. But that doesn’t necessarily mean he harbors fond feelings for either man.

Roger actually met Buck MacKenzie back in colonial times in Outlander Season 5 Episode 7 “The Ballad of Roger Mac.” When Roger was reunited with his ancestor Morag MacKenzie (Elysia Welch), he embraced her, totally unaware that her jealous husband Buck (Graham McTavish) was watching. The enraged Buck beat Roger up and hung him. Only Brianna and her parents arriving just in time to find Roger saved his life.

In the books, Buck and his son time travel to the future via those magical stones. Buck learns that Roger and Brianna are at Lallybroch, so he heads there. Jemmy and Mandy discover him and he convinces them to sneak him food to live off of. Given what we’ve seen on the show so far, it seems likely that Outlander will be sticking fairly closely to the plot in the books. (But then again, we haven’t yet watched past Outlander Season 7 Episode 5, so we don’t know!)