There is a major behind-the-scenes shakeup on Star Trek; Discovery, the upcoming new Star Trek series for CBS All Access, CBS’ live streaming and VOD service. Executive producer Bryan Fuller, who co-created the series with Alex Kurtzman, is exiting as showrunner. His No.2s, Gretchen J. Berg and Aaron Harberts, will succeed him in running day-to-day on the show.

Fuller gave the duo his endorsement via Twitter:

Riker spent 7 years of TNG unready for Captaincy, @GretchenJBerg @AaronHarberts are ready. Thrilled to see them in command of the Bridge. — Bryan Fuller (@BryanFuller) October 27, 2016

It’s been a rough going for Star Trek: Discovery following a splashy announcement, a marquee Comic-Con appearance and a blockbuster Netflix international distribution deal, which paid in full for the show’s budget. Casting and pre-production had been going slowly, leading to the decision last month to push the premiere of the series from January to May. After a five-month search, the series still has not cast its female lead, Lieutenant Commander, though it is getting closer. Filming is slated to begin next month in Canada.

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Fuller, who is still overseeing the breaking of the stories for the first season, has been the public face of Star Trek: Discovery, talking passionately about it at events, so the series is now losing its top ambassador. (He will remain as an executive producer on the show.)

“It is without exaggeration a dream come true,” Fuller said of being named co-creator and showrunner on the new Star Trek series in February. He wrote the first episode and is working on two more. To help fill in the void left by Fuller’s diminished role, the series will be bringing in veteran Akiva Goldsman (Fringe) in a senior writing/producing capacity.

Unlike Fuller, Berg & Harberts as well as Goldsman have no Star Trek experience. Berg and Harberts, who previously worked with Fuller on his cult ABC series Pushing Daisies, had spent the last five years on primetime soaps, including Revenge, Reign and Off the Map, before reuniting with Fuller on Discovery.

In a statement, producer CBS TV Studios praised Fuller’s contributions.

“We are extremely happy with the creative direction of Star Trek: Discovery and the strong foundation that Bryan Fuller has helped us create for the series,” the statement said. “Due to Bryan’s other projects, he is no longer able to oversee the day-to-day of Star Trek, but he remains an executive producer, and will continue to map out the story arc for the entire season. Alex Kurtzman, co-creator and executive producer, along with Fuller’s producing partners and longtime collaborators, Gretchen Berg & Aaron Harberts, will also continue to oversee the show with the existing writing and producing team. Bryan is a brilliant creative talent and passionate Star Trek fan, who has helped us chart an exciting course for the series. We are all committed to seeing this vision through and look forward to premiering Star Trek: Discovery this coming May 2017.”

Fuller also executive produces Starz’s American Gods drama series, which has been in production for six months, though he has a seasoned partner on that in Michael Green. He also has been developing an Amazing Stories reboot for NBC. The news of his Discovery exit was first reported by Variety.