Warning: Spoilers ahead from Sunday’s “Outlander” episode.

Season 3 of “Outlander” has fast-forwarded 20 years into the future — so Laoghaire Mackenzie (Nell Hudson) looked much different in her (middle-aged) return Sunday night after a long absence from the time-traveling Starz series.

“They put me in a wig — which, funny enough, is the same wig Annette Badland, who was Laoghaire’s grandmother, wore [in Season 1],” says Hudson, 26. “That was hilarious. It was like looking into the future if the next 15 years of my life go horribly wrong.”

‘It was like looking into the future if the next 15 years of my life go horribly wrong.’

Laoghaire (pronounced “Leary”) isn’t the only “Outlander” character whose physical appearance has changed this season on the Golden Globe-nominated drama. Jamie Fraser (Sam Heughan), who was in his early 20s in Season 1, now needs bifocals to read. Claire (Caitriona Balfe), who was in her late 20s in Season 1, now has a dash of grey in her dark hair.

“Outlander” revolves around the adventures of couple Jamie and Claire Fraser — she a time-traveler from the 1900s, he a Scottish Highlander living in the 1700s — and their relationship has experienced its fair share of obstacles: from wars to witch trials to depraved Redcoats to two decades spent living apart in different centuries.

‘In an objective way, Laoghaire is a villain. But as with any character … you have to find a way to be on their side.’

But Laoghaire is perhaps their most human obstacle. Her seemingly harmless teenage feelings for Jamie in Season 1 eventually turned to jealous rage directed at Claire — who Laoghaire tried to get killed for practicing witchcraft. “It was like riding a bike,” says Hudson of Laoghaire’s return. [Aside from a brief appearance last season, hasn’t appeared on “Outlander” since Season 1.] “It’s such a nice thing to be able to do — to know it’s there. You go off and do other jobs and forget about it, and then it’s so familiar stepping straight back into the character’s skin.

“In an objective way, Laoghaire is a villain,” she says. “But as with any character … you have to find a way to be on their side. She’s done a lot of terrible things but there are things about her that you can admire. Her love for Jamie has always been the anchor that I go back to when trying to justify her actions.”

Laoghaire reappeared on Sunday’s episode after Claire made the unpleasant discovery that Jaime married Laoghaire during his long separation from his true love. (For his part, Jamie was unaware that he’d ever see Claire again.) Laoghaire wasn’t happy to see Claire again, either, and after threatening her with a gun, shot and wounded Jamie.

“It was quite fun filming something so high-stakes; I hadn’t shot anyone with a gun before in any of my other acting jobs,” says Hudson. And Laoghaire doesn’t only have her grandmother’s hair now — she also has two children with a previous husband, which was another source of amusement for Hudson.

“What was really fun is that Laoghaire has got two daughters, and Lauren Lyle, who plays Marsali, is actually two years younger than me in real life,” she says. “Lauren has become a good friend of mine. Funny enough, in the huge city of London we live on the same street.” And, no matter what happens with Laoghaire’s storyline, Hudson says that she’ll continue watching “Outlander” to support Lauren — “as a proud mother.”

“Outlander” airs at 8 p.m. Sunday on Starz