The Walking Dead's midseason 10 premiere includes a callback to the first season's finale, "TS-19." Taking place roughly two months into the apocalypse, "TS-19" sees Rick Grimes (Andrew Lincoln) and a small band of survivors make their way to the CDC in Atlanta, where they encounter virologist Edwin Jenner (Noah Emmerich). The survivors are horrified to learn they're trapped in the building, set to self-destruct by way of explosives that will set the air on fire as part of a precautionary measure intended to prevent the escape of diseases in the event security is ever compromised.
Before the countdown is activated, Jenner escorts the group through elevators taking them into the belly of the CDC. "Are we underground?" asks Carol (Melissa McBride), at the time a meek mother and the only surviving parent of Sophia (Madison Lintz). When Jenner asks Carol if she's claustrophobic, she says, "Just a little." He then tells her to "try not to think about it."
Some ten years later, in "Squeeze," Carol, Daryl (Norman Reedus), Aaron (Ross Marquand), Jerry (Cooper Andrews), Magna (Nadia Hilker), and sisters Connie (Lauren Ridloff) and Kelly (Angel Theory) are trapped below ground in a cave filled with thousands of walkers. Connie, through ASL, asks a distressed Carol if she's okay. Daryl answers for Carol, telling the group she's claustrophobic.
Later, Carol says she never told Daryl about her claustrophobia. "If I only knew what you told me," he says, "I wouldn't know shit."
Incidentally, another line from "TS-19" finds its way into an exchange between the sisters. Kelly signs to Connie, asking if she thinks it's day or night outside. Connie signs back: "Try not to think about it."
In the midseason 10 finale, Alpha, killer of Carol's son Henry (Matt Lintz), goaded the mourning mother into a pursuit that ended with the group trapped.
It's there Daryl once again urges Carol to call off her vendetta, telling her, "You gotta not bullshit me. Don't bullshit me. You gotta promise. I gotta know we're on the same team. We fight for our future. We don't fight for revenge." Still stung with grief, Carol can't get past her hurt until after Alpha suffers and dies.
"For Carol, the stakes are so high for her because of what happened to her son, and I think in this episode what we're really seeing — and Melissa McBride just portrays the role so beautifully — it's just the depth of her grief and pain and how much of it she's been hiding away from everybody else in the group," showrunner Angela Kang previously told EW after episode 1003, "Ghosts," where Carol engaged in similar reckless behaviors. "And that comes bubbling up to the surface in a couple of really key moments, such as when she's at the border with Alpha. When somebody is going through that much pain, and when they have such a burning desire to have revenge, and when she really wants to see Alpha pay for her sins, that's going to have a big impact on all our people in various ways."
Kang then made mention of actions that have since come to fruition.
"You're also seeing the start of some pretty self-destructive behaviors in this episode. So the season builds from there with her story," Kang said. "So yeah, it's a continuing story for us. It has a lot of emotional depth from her character side."
New episodes of TWD Season 10 premiere Sundays on AMC. For more TWD, follow the author @CameronBonomolo on Twitter.