Warning: This post about Outlander‘s print shop episode contains mild spoilers for possible upcoming events in Season 3.

Even if you’ve committed Diana Gabaldon’s Outlander novel series to memory, there was a moment in Sunday’s episode that likely surprised you — because it’s a pretty large change from the books.

The “A. Malcolm” found Jamie confessing his parentage of young William soon after Claire’s return to 18th century Scotland. In Gabaldon’s Voyager, which provides the framework for Season 3 of the Starz drama, the revelation about his secret son comes much later in the narrative and is bundled with another shocker (for Claire): the knowledge that John Grey is a) gay and b) into her husband.

The book’s scene takes place in Jamaica, where Jamie and Claire head [Spoiler alert!] in search of Young Ian, who’s been kidnapped. It just so happens that John Grey is serving as a governor in the British colony, and when Claire oversees a close moment between her husband and his former warden — the moment he gives Jamie the miniature of William, to be exact — she interprets it as something much different. In fact, in the book, it’s Grey who first alerts Mrs. Fraser to the fact that the young earl of Ellesmere has Fraser blood running through his veins.

“That’s probably the biggest departure we made this season,” star Caitriona Balfe tells TVLine, explaining that the writers’ choice to change the timing of events was because “they felt that maybe it wasn’t believable that Jamie wouldn’t tell her everything.” For what it’s worth, she approves of the switch. “I think it fits very well in that scene where Claire is sharing about Brianna, that Jamie would at that point want to share that he has a son,” she says. “It ended up working very beautifully in that scene. It becomes about the children, their legachy and what they’ve created in this world.”

She adds that she and co-star Sam Heughan asked the writers early on to amplify the discussion of Brianna and William to include the Frasers’ other child. “I was like, ‘Can we please put in just even the tiniest thing about Faith?’,” she recalls. “Because I think anyone who has lost a child or had a miscarriage or anything like that, it’s something they would never forget and that is still part of this family.”

She adds: “That was beautiful, that we have the scene about the three children in their lives.”