Jade Pettyjohn as seen in "Big Sky"

Last year, audiences held their breath over ABC's newest thriller, "Big Sky." As we make our way further into 2021, David E. Kelley's ("Big Little Lies") gripping tale is making its way back to the screen for more heart-stopping action. The mid-season premiere of "Big Sky" airs Tuesday, Jan. 26, on ABC.

The first half of the series starts on a deserted highway in Montana. When sisters Danielle (Natalie Alyn Lind, "The Gifted") and Grace (Jade Pettyjohn, "School of Rock") are kidnapped by a truck driver named Ronald Pergman (Brian Geraghty, "Chicago P.D."), private detectives Cassie Dewell (Kylie Bunbury, "Under the Dome") and Cody Hoyt (Ryan Phillippe, "The Lincoln Lawyer," 2011) join forces with Hoyt's estranged wife and ex-cop, Jenny Hoyt (Katheryn Winnick, "Vikings"). Together, as they work to track down the girls, they soon discover that the sisters aren't the only girls missing in Montana.

With this basic plot information out of the way, it is at this point that we caution any readers who are not up to date with "Big Sky" to continue reading at your own risk: Season 1 Part 1 spoilers lie ahead.

The first half of the ABC series premiere season was emotionally exhausting — but in a good, thriller way — and audiences couldn't exactly make out who the leading bad guy was for quite some time. Ronald, the truck driver, is quick to anger, doesn't think about the consequences of his actions and kidnaps two girls. He also doesn't treat his mother well, and is shown choking her when she accused him of being a pervert. That being said, he appears never to intentionally want to hurt the sisters … unless, of course, they manage to provoke him emotionally.

Former state trooper Rick Legarski (John Carroll Lynch, "The Founder," 2016) teamed up with Cody to investigate the abductions. In a shocking twist, viewers learned that he runs an underground sex-slave trade and hired Ronald to kidnap the girls — all of them. But when Cody started getting too close to his secret, Legarski shot him.

In an act of "what goes around comes around," Dewell stepped in and killed Legarski. Of course, this creates huge problems for her, even though Legarski pulled his gun on her first. Jenny Hoyt, who unlawfully tracked Legarski, was arrested, and now there's no incriminating evidence against the corrupt, presumed-dead ex-trooper. In the law's eyes, Dewell committed murder for no reason.

Bad guys and dropped jaws aside, we can't forget first-season romance entanglements. Cassie and Cody are not only law enforcement partners but romantic partners as well. The problem is that Jenny and Cody are still married. It was only because of Danielle's boyfriend, Justin, who is Cody and Jenny's son, that they got involved with the investigation together in the first place.

Katheryn Winnick, Ryan Phillippe and Kylie Bunbury star in "Big Sky"

Perhaps one of the more significant moments of the season so far has been the introduction of Jerrie's (Jesse James Keitel, "Miller & Son," 2019) character. Jerrie, a nonbinary transfeminine sex worker and aspiring singer, was kidnapped by Ronald prior to Grace and Danielle. Portrayed by Keitel, who also identifies as nonbinary, the representation of a nonbinary trans person by a nonbinary actor is groundbreaking in television. At first, Keitel was uncomfortable with the character, finding Jerrie to be too simplistic. However, after Keitel and the directors sat down and fleshed out the character some more, Jerrie became someone they believe better represents a queer person in 2020.

Jerrie, Danielle and Grace are last seen together in the season's winter finale. The three of them have plotted their escape multiple times from the storage bin in which they're kept and have yet to succeed. Jerrie even tried to convince Ronald to let the other two girls go. He seemed regretful, but we don't know that he'll act on that regret. Even if the girls do manage to make a break for it, no one has any idea how Grace's leg will hold up. (She was shot with arrows, of all things, in episode three.)

Now we are left with a multitude of cliffhangers: Is Cody really dead? Will Ronald let the girls go? What will happen to Dewell? Thanks to ABC, we get six more episodes of Season 1 to find out all of the answers to all of those questions and more. Because Dewell and Jenny are so close to finding the girls, one thing we can only assume is that Kelley will introduce some new storylines into the mix — he has good source material for it, too.

"Big Sky" is based on C.J. Box's novel "The Highway," which is part of a four-part series called The Highway Quartet, which also overlaps The Cassie Dewell Series. The television adaptation has taken its own creative liberties at times — Cody and Cassie being lovers, for one — but has also landed some key plot points from the book. Even though we can't exactly be sure where the next half of Season 1 will go, we can trust Kelley to work out the details for us and possibly source from the other novels in the series. The Quartet's second novel is "The Badlands," which focuses on Cassie solving crimes in North Dakota.

Kelley, the series showrunner and executive producer, is best known for his other work, "Big Little Lies" and "The Undoing." He is a master twist writer and visionary. Still, since his success with "Ally McBeal" and "The Practice" in the late '90s, we haven't seen much of his work on network television. After a series of unsuccessful shows, he switched over to streaming and cable until now, almost a decade later, when he re-entered the network TV scene.

Following a six-week hiatus, fans are itching to see "Big Sky" return to their television sets. Catch the thriller as it wraps up when the mid-season premiere airs Tuesday, Jan. 26, on ABC.