ABC's "Big Sky" is created by David E. Kelley and adapted from the first episode of CJ Box's "Cassie Dewell" novel series "The Highway". "Big Sky" tells the story of private detective Cassie Dewell and former police officer Jenny Hoyt working together to investigate a kidnapping case on a remote highway in Montana, in which two sisters were kidnapped by a truck driver. However, when the two investigated in depth, they found that there were more than two victims. Now the protagonists have to race against time to catch the murderer and prevent him from kidnapping other women.