Adam Is Actually Shauna's Baby

In Season 1, under the impression that her husband Jeff (Warren Kole) is having an affair, 2021 Shauna (Melanie Lynskey) ends up pursuing her own bliss and hooking up with Adam, a young, handsome artist she meets during a small car accident (as it turns out, Jeff isn't having an affair at all, and in one of the season's funniest moments, he's horrified that his wife hasn't been attending "book club" like she claimed). Adam seems pretty innocuous at first, but after she does some digging, she grows suspicious: not only are there a lot of weird gaps in his personal history, but he's also been hiding books and research about her plane crash and subsequent time in the woods. To make matters worse, someone's blackmailing the surviving team members, and none of them know who's behind the threatening communiques.

The Yellowjackets, in their adult years, clearly have some stuff to hide — cannibalism, it's cannibalism — and so when she thinks her past is in danger of being uncovered, Shauna does the only thing she thinks she can do. That is, she stabs Adam and kills him. Ultimately, Adam's not behind the blackmail (Shauna's bonehead husband Jeff is, but that's a different story), and Shauna, Taissa, Natalie, and Misty (Christina Ricci) are stuck with disposing of his body. As the season draws to a close, Shauna's daughter Callie (Sarah Desjardins), who knew about her mother's affair, sees on the news that Adam is missing, and it's pretty obvious that she connects the dots.