Outlander: The story behind that horseshoe, and the latest Easter egg 

For anyone well-schooled on the books of Diana Gabaldon, the presence of a horseshoe aboard the Artemis in Sunday’s episode of

may seem like, well, a ship out of water. The crew’s routine of constantly touching the horseshoe to help with their luck wasn’t included in

, the third book in Gabaldon’s series on which this season is based.

That’s because the writers created it especially for this episode, explains executive producer Matthew B. Roberts. (And here’s a teaser: You’ll see it later too).

“We try to keep with the spirit of the story of the book. And we want to keep Jamie’s seasickness because that’s a big part of his character,” says Roberts. “But we also wanted to make sure we played out Mr. Willoughby’s story, so we felt [the horseshoe] helped to drive it and shows the mentality of the sailors, how they are looking for any excuse to explain their change their luck. The story goes from one person being bad luck to finding another good luck charm. It ends up being Mr. Willoughby.”

That wasn’t the only surprise added to “The Doldrums.” The stern of the Artemis featured an Easter egg from season 2 — a wooden statue that first appeared in the French brothel where Jamie met Bonnie Prince Charlie and young Fergus.

“We were thinking we’d pay someone to carve a new one,” production designer Jon Gary Steele recalls to EW. “But then weeks before we came here, we were walking by all those things that were stacked up [from season 2], because you don’t want to destroy them. Nicki McCallum, the supervising art director who’s brilliant, and I were walking by and both started looking at the statue and I said, ‘Well, this looks like a masthead. Why don’t we just use this?’ It’s kind of fun because it was all done. I mean, all we had to do is a little bit of work on it and repaint it, whatever. But it’s also fun to be able to say to the fans, ‘If you look, you’ll find something that was off that set.’”

pick up the latest issue of EW on newsstands now. And if you’re looking for early scoop on season 4, click here!

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