Joss Whedon's return to series television will boast, as his signature, a big ensemble cast.

His upcoming HBO project, the sci-fi drama "The Nevers," has added 12 series regulars.

In "The Nevers," a group of Victorian women "find themselves with unusual abilities, relentless enemies, and a mission that might change the world."

Whedon will serve as executive producer, showrunner, writer, and director. HBO has yet to set a premiere date.

The new cast members include Whedon's "Dollhouse" alum Olivia Williams, as well as "Grantchester" star James Norton.

Here is the full ensemble lineup along with their character descriptions:

  • Olivia Williams as Lavinia Bidlow – A wealthy spinster and champion of the “Touched”, Lavinia funds the Orphanage (where Amalia and many of the Touched live) through her vast family fortune. She is stern and old-fashioned, but as strong-willed and clever as anyone she confronts.
  • James Norton as Hugo Swann – A pansexual posh boy whose charm has about five years left on its lease. He runs a secret club and a side trade in blackmail. He’s devoted to fulfilling everyone’s worst impression of him – and fascinated by the Touched.
  • Tom Riley ("Dark Heart") as Augustus “Augie” Bidlow – A sweet, disarming nerd and Lavinia’s younger brother. A keen ornithologist, Augie is happy to let his older sister take the reins of the family fortune. He finds the Touched unnerving, but is drawn to them by his increasing infatuation with Miss Adair, and by the schemes of his nefarious best friend, Hugo.
  • Ann Skelly ("Vikings") as Penance Adair – Amalia’s dearest friend, and one of the first women to join her cause. A devout – yet heretically progressive – Irish girl, Penance has genius for invention. She is delighted by her power, and her default is love and acceptance. But she’s firm in her moral sense, and will be guided by what’s right over what’s expedient every time.
  • Ben Chaplin ("Cinderella) as Detective Frank Mundi – Big, gruff, and deeply moral, Detective Mundi trusts no one, least of all himself: his reputation for sudden violence (and excessive drink) is not unwarranted. Frank finds himself caught between the powerful, who ignore the the laws of the land, and newly empowered, who ignore the laws of physics.
  • Pip Torrens ("The Crown") as Lord Massen – Staunch, unflappable and merciless in his defense of the British Empire, this former General, now Peer, may be the only man who sees clearly what havoc these few strange people can wreak upon the established order. Which he will protect, one way or another.
  • Zackary Momoh ("Seven Seconds") as Doctor Horatio Cousens – One of the few successful West Indian physicians in London. Married with a young son, Horatio’s fortunes took a dark turn when he met Amalia and discovered his own ability. Now he works with her, and with the Beggar King, those who don’t care who is or isn’t “different.”
  • Amy Manson ("Once Upon a Time") as Maladie – Committed by her husband (and genuinely unstable), she’s been warped by a power she can’t understand, and tortured by doctors intent on finding its source. She now lives underground, runs a gang and is on an infamous murder spree. She affects a theatrical parody of a bedlam waif, but mad as she is, she’s a woman with a purpose.
  • Nick Frost ("Shaun of the Dead") as Declan Orrun, aka The Beggar King – Charismatic and brutal, Declan runs – or has a piece of – most of the low-level criminal activity in the city. He’s perfectly happy to help Amalia and her cause – and equally happy to sell them out. He backs winners, and the Touched are long odds.
  • Rochelle Neil ("Episodes") as Annie Carbey, aka Bonfire – Annie is a career criminal who landed the ability to control fire and is happy to hire it out. Came up rough, stayed that way, but she’s neither impulsive nor cruel – just looking out for herself. No matter who she works with or for, Annie trusts only Annie, and the fire.
  • Eleanor Tomlinson ("Poldark") as Mary Brighton – Gentle but surprisingly resilient, Mary pursued her dream of singing on stage. A disappointing career and a broken engagement haven’t diminished her spirit. She’s going to be great. She’s going to be very surprised how.
  • Denis O’Hare ("Big Little Lies") as Dr. Edmund Hague – A gifted American surgeon, he uses his skills in the coldest, most brutal way possible. But it’s all in the name of progress!