Frank Spotnitz has departed as the showrunner of the Amazon drama, “The Man in the High Castle,” Variety has learned.

The series, which is based on Philip K. Dick’s novel, is currently in production in its second season in Vancouver. It’s set in 1962 in an alternative reality in which Germany and Japan were the victors of World War II and occupy the U.S.

Spotnitz and Amazon released the following joint statement:

“Given the ambition and scope of the series, the decision has been made to locate all creative efforts on ‘The Man in the High Castle’ to the west coast; Frank Spotnitz will remain as an executive producer and step back from showrunner. His responsibilities will be managed by our deep and talented bench of producers. We are enormously grateful to him for bringing our customers on one of the most watched original shows on Amazon Video and we are excited about the team’s vision for season two.”

A source disputes reports that Spotnitz’s exit was due to the producer being hands-off, instead pointing to creative differences with the studio, but confirms that production has been halted.

The pilot first debuted on the streaming service in January 2015, and went on to become one of the most-watched on Amazon. The 10-episode debut season premiered in November, with Variety‘s Maureen Ryan calling it a “handsome series, which expands the Philip K. Dick novel into a thoughtful meditation on the ways in which oppression worms its way into relationships and the fabric of societies.”

“High Castle” hails from Ridley Scott’s Scott Free Prods. Along with Spotnitz, Ridley Scott exec produces with David Zucker, David Semel and others. Rufus Sewel, Alexa Davalos, Rupert Evans, DJ Qualls and Joel de la Fuente star.

The series was a passion project for Spotnitz, who had long been attached to it. After Scott had struck out with a version of the project at the BBC several years ago, Spotnitz came on board as the show was redeveloped for Syfy, which ultimately ended up passing as well.

“Amazon is spending a hell of a lot of money. It’s the biggest gamble I’ve ever been associated with,” Spotnitz told Variety last year. “[Subsequent episodes don’t cost] as much as the pilot, but it’s still an awful lot of money and we have the same creative team as the pilot. We’ve invested a lot in the look of the show and the one good thing about world-building is, once you’ve established it, you have it in your library and it is amortized over time.”

Amazon approached Spotnitz about reviving the project as the company ramped up its production of original hour-long series. Amazon head of drama Morgan Wandell and Spotnitz had worked together previously on an ABC series.

News of his exit was first reported by Deadline.