Pennyworth’s Anna Chancellor and Outlander’s James Fleet have joined the cast of BBC America’s The Watch, based on Sir Terry Pratchett’s Discworld novels.

The pair are the latest actors to join the BBC Studios and Narrativia-produced series, joining lead Richard Dormer.

Chancellor stars as Lord Vetinari, The Patrician of Ankh-Morpork, and architect of the city’s normalized wrongness and ramshackle system of governance, while Fleet stars as The Archchancellor, wizard, magical advisor, and the Head of the Unseen University.

Set in the fictional city of Ankh-Morpork, where crime has been legalized, The Watch is a “punk rock” drama. The eight-part series centers on a group of misfit cops as they rise up from decades of helplessness to save their corrupt city from catastrophe.

Elsewhere, Ingrid Oliver (Doctor Who) stars as the Head of The Assassins’ Guild, Doctor Cruces. Ruth Madeley (The Rook) stars as the wiry Throat, the city’s best snitch, with a gang of freelance henchmen at her beck and call. Hakeem Kae-Kazim (Dynasty) stars as Captain John Keel, former leader of The Watch and mentor to Sam Vimes, determined to save the corrupt and chaotic city and Bianca Simone Mannie (Homeland) stars as the cunning Wonse, a wizard hopeful in waiting that is frequently underestimated.

They join previously announced Adam Hugill (1917), Jo Eaton-Kent (Don’t Forget The Driver), Marama Corlett (Blood Drive), Lara Rossi (Crossing Lines) and Sam Adewunmi (The Last Tree).

It is written by The Musketeers and Das Boot writer Simon Allen, along with Joy Wilkinson (Doctor Who), Catherine Tregenna (Torchwood), Amrou Al-Kadhi (Little America) and Ed Hime (Skins). The series is exec produced by BBC Studios’ outgoing Head of Drama London Hilary Salmon, who has worked on series such as Luther and Silent Witness, Ben Donald and Wilkins as well as Richard Stokes (Torchwood), Rob Wilkins (Good Omens), Craig Viveiros and Allen. Johann Knobel (Shameless) is series producer of The Watch, and Simon Rogers (Doctor Foster) is production designer. BBC Studios is handling distribution internationally.

It was commissioned by Sarah Barnett, President, AMC Network’s Entertainment Group & AMC Studios when she served as President and GM of the network. Craig Viveiros (Agatha Christie’s And Then There Were None) is set to direct with Brian Kelly (Outlander) and Emma Sullivan (Doctor Who). It films in Cape Town, South Africa at the end of this month and will air in 2020.

Chancellor said, “It’s been so exciting to join such a wonderfully creative team – from writer Simon Allen to the stunning production design and a truly talented group of actors – to help realize Terry Prachett’s brilliantly anarchic yet strangely real and moving world. With the combining characteristics of Dracula and Elvis – Lord Vetinari has sprung to life in the most alarmingly joyful way”

Fleet added, “I’m delighted to be playing the Archchancellor. I think the writing and design catch the spirit of Terry Pratchett’s work and create a world of jeopardy and humor.”