An “Outlander” prequel series is in development at Starz, Variety has learned exclusively.

According to sources, “Outlander” executive producer and showrunner Matthew B. Roberts is attached to write and executive produce the prequel. A writers’ room is currently being assembled with an eye to begin work in the coming weeks.

Exact plot details for what the prequel would focus on are being kept under wraps. Ronald D. Moore, who developed “Outlander” for television, will also executive produce along with Maril Davis under their Tall Ship Productions banner. As with “Outlander,” Sony Pictures Television will be the studio. Roberts is currently under an overall deal at Sony.

Reps for Sony and Starz declined to comment.

“Outlander” is based on the ongoing novel series of the same name by Diana Gabaldon. Gabaldon recently teased in a Facebook post that she is still working on a prequel novel about Ellen MacKenzie and Brian Fraser, the parents of “Outlander” main character Jamie Fraser. Gabaldon also published the prequel novella “Virgins” in 2013 as part of the “Dangerous Women” anthology. That story focused on a young Jamie Fraser and Ian Murray in 1740s France. However, there is no indication at this time that either story would be the focus of the prequel series.

News of the prequel comes as Season 6 of “Outlander” is due to bow on Starz on March 6. A seventh season has already been greenlit. Production on Season 6 was delayed due to the COVID-19 pandemic, which pushed back the premiere date. Season 6 is based on the “Outlander” book “A Breath of Snow and Ashes,” and will consist of eight episodes. Season 7 is based on “An Echo in the Bone” and will consist of 16 episodes.

The move to expand the “Outlander” universe at Starz comes as little surprise, given that the series remains one of the premium cabler’s most popular shows even this late in its run. Starz has also had success building out franchises around other shows in its lineup, most notably “Power.” As the mothership show ended in 2020, the network greenlit four spinoffs. Three of those have already premiered, with the most recent being “Power Book IV: Force” starring Joseph Sikora. The other two that have aired — “Power Book II: Ghost” and “Power Book III: Raising Kanan” — have already been renewed for a third and second seasons respectively.

Roberts is repped by CAA and attorney Ken Richman.