"His Dark Materials" is now filming in Cardiff, Wales. According to Deadline, this series adaptation of Philip Pullman's fantasy novels is "thought to be one of the most expensive British dramas to date."

The full cast was just revealed, adding more names to the already impressive lineup led by James McAvoy, Dafne Keen, and Lin-Manuel Miranda.

Here's a description of the characters and cast, via the BBC:

"Dafne Keen takes on the lead role of Lyra, the young protagonist of the story who lives in Jordan College, Oxford. Placed there at the request of her Uncle, Lord Asriel (James McAvoy) she lives a sheltered life amongst the scholars and college staff while under the watchful protection of The Master (Clarke Peters) and Librarian Scholar Charles (Ian Gelder).

When the glamorous and mesmeric Mrs Coulter (Ruth Wilson) enters Lyra’s life she embarks upon a dangerous journey of discovery from Oxford to London. Here she meets Father MacPhail (Will Keen), Lord Boreal (Ariyon Bakare) and journalist Adele Starminster (Georgina Campbell) at a glittering society party where she first hears about the sinister General Oblation Board.

Lyra is subsequently thrown into the nomadic world of the boat dwelling Gyptians - Ma Costa (Anne-Marie Duff), Farder Coram (James Cosmo), John Faa (Lucien Msamati), Raymond Van Geritt (Mat Fraser), Jack Verhoeven (Geoff Bell) and Benjamin de Ruyter (Simon Manyonda) who take her North in her quest.

Once in the North she meets charismatic aeronaut and adventurer Lee Scoresby (Lin-Manuel Miranda) who joins them on their epic journey and who becomes one of Lyra’s closest allies."

The series was written by Jack Thorne ("Harry Potter and the Cursed Child"), withJoel Collins ("Black Mirror") as prroduction designer.

Here's a statement from Jack Thorne:

"His Dark Materials are the most beautiful set of books, taking us into a world of constant imagination. Reading them I was a massive fan, in adapting them I've increasingly felt in awe of them. It's the constant invention, the way the story never sits still, and that the characters constantly surprise you. It's been a joy being part of a creative team for this; from Tom's incredible analytic mind and amazing eye, to Joel's beautiful world building, to everyone else involved. And then there's the cast, which has proved to be the cast of dreams, we are so lucky to have been able to entice them in."

In terms of international broadcast -- i.e., how we can eventually watch this in the U.S. -- Deadline said Apple and Netflix are among the suitors for global rights. Stay tuned on how that's resolved. But so far it sounds like a streamer is going to end up with it.

The first novel in "His Dark Materials" -- "Northern Lights" -- was not-so-successfully adapted in the 2007 film "The Golden Compass," which diluted many key themes of the story. Fans are hoping this more expansive series will retain the author's original vision.

Want more stuff like this? Like us on Facebook.