Adapting popular books can be a thorny process. Starz has done it successfully with Outlander, but maybe a little less successfully with American Gods. Next, the cable network will take on The Rook, the spy series written by Daniel O'Malley.

The book and the series both center on Myfanwy Thomas (Emma Greenwell), a woman who wakes up next to London's Millennium Bridge with no memory of who she is and a circle of dead bodies around her. She eventually comes to find out that she's part of a British secret agency for people with paranormal abilities called Checquy.

"David O'Malley invented [a] really intriguing, bizarre British agency that we discover Myfanwy is a part of," executive producer and co-showrunner Karyn Usher told reporters at the Television Critics Association winter press tour on Tuesday. "We spend more time in this season ... exploring who Myfanwy is. Her primary concern is her own identity, trying to figure out who she is. She has lost her memory and everything she touches is a clue, trying to figure out her past and what happened. That general premise we took from the book. The world we took from the book."

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Emma Greenwell and Olivia MunnEmma Greenwell and Olivia Munn

While the premise will feel familiar to fans of the novel, the producers acknowledged that they will be fleshing out more of Myfanwy's backstory, spending more time with Myfanwy before she lost her memory and increasing the roles of Monica Reed (Olivia Munn) and Linda Viscountess Farrier (Joey Richardson) — the three female leads of the series.

However, the show will keep the dark feeling of the show. Kari Scogland directed the first two episodes of the series and set up a very specific tone for the rest of the season.

"She focused on enhancing the paranoia that Myfanwy was feeling, but also the overall tone of the show has that paranoia. She did a great job at setting the aesthetic that everyone else followed," co-showrunner Lisa Zwerling explained.

That tone and the general direction of the show is different from how the show started when Starz originally picked it up though. Twilight author Stephanie Meyer was attached but has since left the project. Executive producer Stephen Garrett also addressed that departure and explained the creative teams and Meyer are still on good terms.

"What happened with Stephanie is that there was potential to pursue a path that she had originally seen in the path and then there was the path that we eventually trod and you're now seeing. It's just a different way of telling the same story. They're just different right answers," he said. "There comes a point, and I've had this experience on the other side of it, where you take it in a direction where you part company. You part company as friends because there's another path. ... It was a natural evolution of different possibilities of the idea. Stephanie in a very grown up and friendly way decided to move on."

The Rook premieres in Summer 2019 on Starz.

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