Dickens will play Nancy Tomkins, a guidance counselor who is dating a divorced teacher. The teacher—played by Gang Related and The Missing actor Cliff Curtis—is the spin-off's male lead, a.k.a. its Rick Grimes equivalent.
Though she might look like the girl next door, Dickens' character is described as having a troubled past that will come back to haunt her. She has two children from a previous marriage, played by Frank Dillane and Alycia Debnam Carey.
Production on the Los Angeles-based project will begin in early 2015.
In addition to Gone Girl and Deadwood, Dickens' acting credits include Treme, Friday Night Lights, and Sons of Anarchy. She is also set to recur on the third season of House of Cards, which premieres in February.