It follows protagonist Myfanwy Thomas as she attempts to re-integrate into her life of administrating a clandestine government organization responsible for protecting the U.K. from supernatural threats.

Inside is a letter that tells her the body previously belonged to Myfanwy (rhymes with Tiffany) Thomas, who worked in a secret government organization and was targeted by an unknown assassin.

She is left with a binder that outlines the organization known as the Checquy ("sheck-ay") which combats the supernatural and unnatural forces that threaten Great Britain.

She also discovers that many recent troubles are due to the Grafters, a group of Belgians who conducted intensive research into genetic and surgical modification and used that knowledge to create inhuman super-soldiers.

Grantchester attempts to have Myfanwy's mind wiped again, but she fights back and successfully kills two of Gestalt's bodies in the process.

Despite her uncertainties regarding the threat the Grafters still pose to the Checquy, Myfanwy agrees to create a meeting with the remaining members of the inner court.

[9][10][11] MTV's Alex Zalben stated that the book was "a wholly refreshing, original piece of work that recalls many, many other previous fantasy universes while creating one of its own that will be worth revisiting again and again.

[14] In 2018, Emma Greenwell as Myfanwy Thomas, Joely Richardson as Linda Farrier, Olivia Munn as Monica Reed, Adrian Lester as Conrad Grantchester, the Gestalt siblings, Ronan Raftery as Robert Gestalt, Catherine Steadman as Eliza Gestalt, Jon Fletcher as Teddy and Alex Gestalt, Ruth Madeley as Ingrid Woodhouse, Shelley Conn as Danielle Wulff, Gina McKee as Jennifer Birch, Barry Atsma as Peter Van Syoc, Luke Roberts as Marcus Kevler, Michael McElhatton as Lorik, Tamsin Topolski as Bronwyn, Myfanwy's sister, Aidan O'Callaghan as Alan, James D'Arcy as Andrew Bristol, and Michael Karim as Nazim were cast ,[15][16] while Paula Patton was cast as the lead villain.