James Marsden (Westworld), as we previously reported was in talks, has closed his deal for a lead role in The Stand, an adaptation of Stephen King’s novel at CBS All Access. Also starring with him are Amber Heard (Aquaman), Odessa Young (Assassination Nation) and Henry Zaga (13 Reasons Why) in the limited event series from CBS Television Studios. The streaming service also announced that King will write the last chapter of the series, providing a new coda that won’t be found in the book.

Written by Josh Boone and Ben Cavell, The Stand is King’s apocalyptic vision of a world decimated by plague and embroiled in an elemental struggle between good and evil. The fate of mankind rests on the frail shoulders of the 108-year-old Mother Abagail and a handful of survivors. Their worst nightmares are embodied in a man with a lethal smile and unspeakable powers: Randall Flagg, the Dark Man.

Marsden will portray Stu Redman, an ordinary working-class factory man in an extraordinary situation with a damaged quality to him that belies his exterior.

Heard will play Nadine Cross, a deeply conflicted woman who feels the consequences of her actions, but is still compelled by her allegiance to Randall Flagg, the Dark Man.

Young is Frannie Goldsmith, a pregnant young woman navigating a strange new world, who also has the foresight to recognize that there is evil lurking beyond the Dark Man.

Zaga will portray Nick Andros, a young deaf and mute man who finds himself in a position of authority when the unthinkable happens. He has a habit of risking his own well-being for the safety of others.

The series will be produced by CBS Television Studios. Boone and Cavell will executive produce, with Boone also directing. Roy Lee, Jimmy Miller and Richard P. Rubinstein will also serve as executive producers with Will Weiske and Miri Yoon as co-executive producers. Knate Lee, Jill Killington and Stephen King’s son, Owen King, will serve as producers.

Marsden most recently seen on the hit dark comedy Dead to Me. His other credits include Westworld and 30 Rock, and he will also appear in FX’s upcoming Mrs. America. In film, he will soon star in the live-action/animation hybrid film Sonic the Hedgehog and The Comeback Trail opposite Robert De Niro, Morgan Freeman, Tommy Lee Jones and Zach Braff.

Heard recently starred in Warner Brothers’ box office hit Aquaman opposite Jason Momoa. She can currently be seen in Alex Ross Perry’s Her Smell alongside Elizabeth Moss.

Young will next be seen opposite Elisabeth Moss in the film Shirley. Her other film credits include Assassination Nation, A Million Little Pieces opposite Aaron Taylor-Johnson and The Professor.

Zaga can be seen in Netflix’s 13 Reasons Why, which was just renewed for a fourth and final season, and the upcoming Trinkets as well as Looking for Alaska, which is currently in production. He will also be seen in Josh Boone’s X-Men: New Mutants.