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'It begins with absence and desire. It begins with blood and fear. It begins with a discovery of witches.'

A Discovery of Witches (TV series) type TV Show network Shudder

A Discovery of Witches, based on the best-selling All Souls Trilogy from Deborah Harkness, has found its Matthew and Diana.

British actor Matthew Goode, known best for his roles in period pieces like The Imitation Game and an arc on Downton Abbey, and Australian actress Teresa Palmer (Hacksaw Ridge), will headline the upcoming series from Bad Wolf Television and Sky Original Productions.

Image zoom Charley Gallay/Getty Images; Dominique Charriau/Getty Images. Inset: Penguin Books

Capitalizing on the trend of developing best-selling fantasy novels for television, Sky Original Productions and Bad Wolf Television are producing A Discovery of Witches for the small screen. Bad Wolf is the production company of former Doctor Who producers Jane Tranter and Julie Gardner.

Harkness will also executive produce, and Kate Brooke (Mr. Selfridge, The Forsyte Saga) will head up the writing team and act as showrunner.

Tuesday's highly-anticipated casting news is six years in the making; A Discovery of Witches debuted in 2011. Producers touted it heavily on social media, including teasing the announcement on Instagram.

British television giant Sky will air the series in the U.K., and a U.S. network will be announced in the coming weeks. The series is slated to begin shooting its first season on location in Great Britain this fall.

A Discovery of Witches follows Diana Bishop, a science historian who also just happens to be a witch with a troubling past that has led her to suppress her magical tendencies. When her research leads her to uncover a mysterious missing manuscript in Oxford's Bodleian Library, she sets in motion a series of events that will lead her on an adventure across time and continents to discover the secrets of her past and the truth about the origin of magical beings (which includes witches, vampires, and daemons). Along the way, Diana also encounters and falls in love with Matthew Clairmont, a scientist and vampire with a murky past of his own.

Juan Carlos Medina (The Limehouse Golem) will direct the series' pilot episode.

Harkness, a history professor at the University of Southern California, drew on her own experiences as a historian of science (and her knowledge of real historical figures) to craft her best-selling series. She is known for engaging with her fans directly over social media, and this casting announcement was no exception, with the news breaking on Facebook and Twitter pages via a special video.

Harkness also prepped fans over the weekend, teasing that a big announcement involving the series would come on Tuesday. <iframe src="https://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2FAuthorDeborahHarkness%2Fposts%2F10155745088746812&width=500" width="500" height="751" scrolling="no" frameborder="0" allowtransparency="true" class="" allowfullscreen="" resize="0" replace_attributes="1" name=""></iframe>Óys½œÓ‡ïg½ÙÝyñýZi§ÜÓWy{Íüo­Þ

She also took care to address the backlash that sometimes comes with such casting announcements, reminding fans that this is where the TV adaptation moves from "fantasy to reality" and calling for "empathy" and "good will."

"We are about to reach the end of that period when we have all, in our own ways and according to our own tastes, imagined the characters into being," she wrote. "None of our imaginings will exactly agree with the fine actors who have been cast in these demanding roles. Can you imagine how thrilling and daunting it is to know that you are going to be occupying the shoes of Diana, Matthew, or any of the other characters?? I can't. I'm not sure I would have the courage."

She also reassured fans about inevitable changes from page to screen. "The TV show (which is called A DISCOVERY OF WITCHES by the way) will not be the books. It cannot be the books," she wrote. "I will explain all the ways in which the TV show is bigger than the books and less than the books in due course but please do rest assured that so much care has been taken on this project, with YOU in mind. I have been part of every decision made, and support each and every direction we have taken thus far even when we have had to diverge from something in the books in order to tell you a good story in a broadcast timeframe."

Producers and Harkness promise that more news about the series, including the U.S. network and further casting details, will continue to be revealed in coming weeks.