Written and executive produced by Kelley, The Big Sky is a procedural thriller about P.I. Cassie Dewell and ex-cop Jenny Hoyt (Winnick), who investigate the kidnapping of two sisters (one of whom is the girlfriend of Jenny's son) by a truck driver in Montana. Cassie, Jenny, and Jenny's estranged husband — another P.I. and Cassie's partner, Cody Hoyt (Ryan Phillippe) — team up to work the case, only to learn that these aren't the only young women to have disappeared. The trio must try to stop the killer before they strike again. John Carroll Lynch and Dedee Pfeiffer also star.
Winnick was an original cast member on Vikings, playing the shieldmaiden Lagertha from 2013 until her character was written off the show in the fall of 2019. Vikings is halfway through airing its sixth and final season, which is expected to return later this year. Winnick's other credits include Bones, Polar, and the upcoming film Flag Day.