Outlander aficionados might be onto something with a theory about Emily’s eldest son, Swiftest of Lizards, who they reckon could actually not be Young Ian’s biological offspring.

Since the Outlander season 7 finale graced our screens back in January, there’s just one more season left before bidding adieu to the TV adaptation.

That’s leaving fans with a heap of unanswered queries concerning their favourite characters. Conventional wisdom suggests Young Ian fathers Emily’s son, deduced from the child’s pale complexion and distinct features, reports the Scottish Daily Express.

But one fan re-investigating Diana Gabaldon’s novels, which spawned the celebrated Starz show, previously sparked debate on Reddit.

A Redditor going by @negotiate stirred the pot asking: “Is Ian the biological father of Swiftest of Lizards?

“I always thought that Ian and Swiftest of Lizards had a spiritual bond only, not a biological one.”

They expanded: “Like Ian was always supposed to have a child with Emily, but when he couldn’t and left the tribe, the ‘spirits’ of the tribe had Emily conceive a child that was spiritually the son of Ian.”

Delving deeper, they mused: “Now reading through the book again, I see that after Emily’s final miscarriage, Ian and Emily continued trying, but the heart had gone out of her.”

They concluded with some speculation: “And then her eye started to stray to Sun Elk, and Ian left the tribe. So that would mean that SOL could potentially be the biological son of Ian. Theories?” (sic)

In the comments section, fans weighed in on the theory. One fan argued: “You had it right the first time. If you remember Claire’s explanation to Ian about his blood being Rh+ and Emily’s being Rh-, that almost completely rules out their having a child together.

“Severe cases of Rh disease cause stillbirth, which is how every one of Emily’s pregnancies ended. I’m not a doctor, but I’ve read that the effects become worse with every Rh incompatible pregnancy.

“If Ian and Emily experienced the worst effects of Rh disease with the first pregnancies, she is not going to carry a child to term later on with Ian as the father. Swiftest of Lizards represents the child they wanted, but couldn’t naturally have.” (sic)

Another fan countered: “Good point but I’m thinking it’s not entirely impossible since Claire implied that that was the issue between her and Jamie. Brianna was born after faith so I do think its possible. Then again, Claire was in the modern world and maybe they were able to treat it.

“I just looked at a genetics chart: if Emily is (–) and Ian is (+-) the child has a 50/50 chance of being (–) or (+-) so I’m guessing its possible for swiftest of lizards to be rh negative.” (sic)

A third fan chimed in: “I think he is Ian’s son. Possible *spoiler* I read Diana’s daily lines so this could be from MOHB or Echo (I’m all mixed up) and there was mention of Ian talking to Rachel about swiftest of lizards because he wants to explain everything before marriage.”

One fan pointed out: “It was strongly implied that he is Ian’s son. Didn’t he also tell his father with the implication that he has a son? I mentioned my medical reasoning on someone else’s comment.” (sic)

Another fan commented: “I haven’t reread in a while, but I thought that Swiftest of Lizards was Ian’s biological son each time I read that passage.”