It can be hard to make science sound sexy. But if any show was going to do it, it undoubtedly was going to be Outlander. (My pseudo-apologies to The Big Bang Theory.) In the Season 4 premiere, Jamie and Claire discuss the first law of thermodynamics and it leads to the notoriously passionate pair to (what else?) make love. Jamie doesn't need to understand the laws of physics to demonstrate the raw heat they have between them. But the romance from this Outlander scene stems less from Claire's science lesson and more from what Jamie has to say about their love. And much of his dialogue was taken directly from the pages that Diana Gabaldon had written more than 20 years before the episode premiered.

Based on Chapter 16, "The First Law of Thermodynamics" from Drums of Autumn, the "America the Beautiful" scene is faithful to the words Gabaldon wrote. But the why, when, and where differs. Written by Outlander mainstays Matthew B. Roberts and Toni Graphia, here's how the thermodynamics scene in the Starz adaptation compares to the book version.

Book spoilers ahead for Drums of Autumn.

The Time & Place

The scene in the book takes place after Stephen Bonnet attacks them, after they visit River Run for the first time, and after Jamie fights a bear... so the show's version took place quite a bit earlier. If the show had wanted to stay true to the timeline of Drums of Autumn, they could have had the thermodynamics scene at the end of "The False Bride" where Jamie and Claire eat strawberries and decide they will take Governor Tryon's offer and settle in the mountains of N.C. — and in fact, that is where the scene originally was, as can be seen in the annotated script for "The False Bride."