Neil Gaiman has signed an overall deal with Amazon Studios to work exclusively on new series for Amazon Prime Video, which will launch them globally. The deal comes as the streaming service prepares for the debut of “Good Omens,” based on the novel co-authored by Gaiman, and as work continues on a second season of his “American Gods.”

Jennifer Salke, head of Amazon Studios, announced the deal with Gaiman during an Amazon show-and-tell in London on Tuesday. The agreement sees Gaiman move to Amazon from production and distribution giant Fremantle, with which he had signed a first-look deal in February 2017 and which produces “American Gods.” That deal was touted at the time as a multi-year partnership. A spokesperson for Fremantle said only that the pact “has now expired” but that Fremantle is continuing to work with Gaiman on “a number of projects” hatched while it was in force.

The financial details of the new agreement between Gaiman and Amazon were not disclosed.

“Neil Gaiman is a phenomenally talented writer, who creates worlds that are compelling, multi-dimensional and narratively unique,” Salke said. “His fans are ardent, vocal and passionate, and we are fortunate to bring his gifted vision to the Prime Video audience. ”

Gaiman said the experience of working with Amazon on “Good Omens” had swung it for him. “They are smart, gloriously enthusiastic people, who weren’t afraid of ‘Good Omens’ being different but who were as determined as I was to make something as unique and exciting as it is,” he said.

The show stars Michael Sheen (“Masters of Sex”), David Tennant (“Doctor Who”) and Jon Hamm (“Mad Men”) in a darkly comic take, complete with angels and devils, on the coming of Armageddon. Gaiman and his “Good Omens” co-author, Terry Pratchett, who died in 2015, had long wanted to see their book translated to the screen, first as a film, then for TV.

Gaiman said Tuesday that he spent 18 months writing six episodes, “reinventing it as television while trying to stay faithful” to the text. “It’s absolutely a book that believes in humanity….It’s a book about friendship.”

“There’s a tone to the book that is very lighthearted even though it’s dealing with the end of the world,” Hamm added. “When people ask me what it’s about, I say, ‘Well, it’s a comedy about the apocalypse.'”

Gaiman is credited with being one of the creators of modern comics. His work extends to comics, poetry, film, journalism, song lyrics and, to an increasing extent, TV.

The television adaptation of “American Gods,” which ran on Starz in the U.S., received generally good reviews for its first season. But production of the eight-episode second season has run into setbacks, including the departure of the original showrunners, Michael Green and Bryan Fuller, and now the reported sidelining of their replacement, Jesse Alexander.

Gaiman’s first-look deal with Fremantle, in February 2017, was announced as a multi-year partnership. Both parties were quoted at the time as saying that they were already exploring new projects.

But “Good Omens” was commissioned by Roy Price, Salke’s predecessor at Amazon, from BBC Studios, Narrativia (which owns the multimedia rights to Pratchett’s works) and Gaiman’s The Blank Corporation.

“I’ve spent years saying to people ‘I would love to make this,’ and they have gone ‘yeah, but that’s too weird,’” Gaiman said. But at Amazon, the response has been more along the lines of “yes, we would love to make this.”