“Outlander” fans frequently applaud the Starz drama for being faithful to Diana Gabaldon’s books, but Season 2, episode 11 may be the installment that stays most true to the author’s vision because Gabaldon herself was able to write it. Stars Sam Heughan and Caitriona Balfe, who play Jamie and Claire, respectively, were thrilled to read the script.

“When we all did the read-through, we were delighted,” Heughan told the Los Angeles Times. “It read really well, there’s a great pace to it.” The episode, titled “Vengeance Is Mine,” will air June 18. Starz hasn’t released a synopsis yet, so viewers looking for hints will have to wait until the episode trailer makes its debut Saturday night.

Gabaldon announced her first foray into TV writing at San Diego Comic-Con last July. Her followers have been waiting since then for the episode, but they’re anxious to see another project come to fruition, too: her next book. She had to balance writing the episode with working on the ninth novel in the “Outlander” series. “It was funny,” Balfe said. “You could see her. It’s almost like she goes off into this imaginary world where she’s sort of talking to herself and seeing it play out ... then you see her go back to the writing. It’s amazing to watch somebody go through that process.”

Balfe doesn’t just read Gabaldon’s scripts. She also has read the books. In fact, she revealed that it was the novels that made her very excited to audition for “Outlander.” She was given only two scenes from the script at that time, but the source material gave a clearer picture of Claire’s identity. “She just felt like a very well-rounded, fully formed character,” Balfe told Rolling Stone magazine in describing her initial thoughts on Claire. “It felt like it would be a really exciting experience to portray her.”

Although the author knows her characters better than anybody else, she is still happy to let the writing team at “Outlander” pen the majority of the season’s episodes. Heughan revealed that the “Outlander” Season 3 premiere has already been written and been approved by Gabaldon. She still has plenty of opportunities to write for the show, though. Starz renewed the time-travel drama for Seasons 3 and 4.

“Outlander” Season 2 airs on Starz Saturdays at 9 p.m. EDT.