Sunday's The Walking Dead was the most flashback-heavy episode since Season 6's "Here's Not Here," which filled in Morgan's (Lennie James) backstory between Seasons 3 and 5. Season 9, Episode 10 took on a similar format, where a character told another the story of how they got there (and in both episodes, at least one of those characters was a prisoner). In "Omega," teenage captive Lydia (Cassady McClincy) told Henry (Matt Lintz) and then Daryl (Norman Reedus) the traumatic tale of how her mother became Alpha (Samantha Morton), the fearsome leader of the skin suit-wearing Whisperer group.

This episode was not as satisfying as "Here's Not Here," but that's one of the best episodes of the whole show. This one wasn't as important. But it did give some valuable backstory and character development for the show's new adversaries and allow Daryl to show his sensitive side, which is always nice.

The episode started with Lydia telling her cellmate Henry a story to pass the time while they sat in Hilltop's jail. Lydia came from Baltimore, and at the start of the outbreak she and her parents were down in a bunker with some other people. In little Lydia's memory, her mother sang to her because she was scared while her father skulked around with a mean look in his eye, wanting to leave. Lydia said her father was a stupid man, and that's why he's dead now. But Henry and Lydia bonded over having tough moms you don't want to mess with.

When Henry started to tell Lydia about the Kingdom, where his family lives, Daryl pulled him out and chided him for sharing information with her, because what if she communicates that info back to her group? Henry was acting like he could trust her, which Daryl said he couldn't do. "She's a good person who got messed up," Henry insisted. Someone being a "good person" and what that means came up many times throughout the episode. Mostly it means being willing to help someone rather than killing them. This is The Walking Dead, where every conversation eventually comes back to dying or surviving.

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Daryl went down to talk to Lydia and asked her what her mom would do if she caught any of his people out in the woods, and Lydia said she would do what she had to (and remember, she caught Luke [Dan Fogler] and Alden [Callan McAuliffe]). This triggered a memory of Lydia watching her mother strangle a bunkmate who was being too loud. It started to seem like maybe Lydia's memory of her parents was a little faulty. "There's a lot of good people here," Daryl told her as he gave her some water. "They'll help you if you help them." She tried to grab him, and he noticed welts on her arm.

He came back later that day carrying a switch from a tree and reflected on the type of dad who beats his kids, a personality type with which Daryl is familiar. Lydia's dad doesn't sound like that type, but those welts on Lydia's arm show that someone has been beating her.

"Where is she?" Daryl asked.

"Be glad you don't know," Lydia answered, finally starting to admit that her mom is a beast.

"You're safer here," Daryl said.

"This place isn't real," Lydia said, referring to Hilltop and the attempt by the people who live there to rebuild civilization. "The world changed and you're all acting like it's gonna change back. She walks because that's what the dead do. It's their world and we have to live in it." She said Alpha beats her for a good reason: "When you stay soft people die."

Daryl told her that they're building the world back up and changing it back to how it was, and Lydia basically Sure, Jan-d him, telling him that he's hard and doesn't belong with these people, an idea that Daryl has indeed been struggling with.

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Outside, Henry told Daryl that Daryl may act like a brute, but he can tell he's secretly kind, and that Lydia's not beyond help. Daryl can make her feel welcome. That night, Henry, infatuated with Lydia, came back to break her out. As they walked through the Hilltop, Lydia picked up a hammer and considered using it on Henry until she heard a baby crying. This caused her to freak out and say "She's a good person" over and over again. She asked Henry to put her back in her cell because she didn't want to go back to her mother. Henry slept in the cell next to her so that she wouldn't be alone, and they held hands.

Daryl came in the next morning and found them there, and Lydia was finally ready to get honest. "My mom's not coming for me," she said. When someone dies, the Whisperers move on, like the dead person never existed. Lydia wanted to go back with intel so her mother would find her useful enough to allow to return. Deep down, she always knew what her mom was and what she did.

And then Lydia shared her final flashback: Her mother wanted to leave the bunker and her father didn't, so she slashed his throat. We didn't actually see it happen, because Daryl stopped her, like, "I get it, you don't have to say it in full gory detail," but Lydia saw her mother cold-bloodedly murder her father when she was about 5 years old. Alpha is not a good person. Then there were some brief flashes of Alpha telling Lydia to put on a skin mask, because that's her thing now.

Daryl seemed convinced that Lydia should be allowed to stay, because she was just a traumatized kid who needed help. But just then, some Whisperers rolled up to the Hilltop. One came up to the gate without her mask. She had her head shaved to the skin and filth around her eyes and mouth. She looked nuts.

"I am Alpha," she said. "And we only want one thing from you: my daughter."

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So was Lydia wrong when she said her mother wouldn't come back for her, or was she lying? We don't know yet. Lydia may have realized that she could manipulate Daryl and Henry better by telling them the facts about where she came from while still concealing her true feelings and motives. She seems like a slippery character. Cassady McClincy is doing a good job playing her. Between this and her role as child psychic Molly Strand on Castle Rock, McClincy is carving out a niche for herself playing creepy kids on horror TV shows.

Not everything in this episode worked. Samantha Morton's Cajun accent is going to take some getting used to, especially since her character came from Baltimore. And the genesis of the skin suits got glossed over, even though that's probably the most interesting thing about these characters. Hopefully more on how Alpha got that idea is coming later in the season. And the B-story about Magna (Nadia Hilker) & Co. being wishy-washy on whether to stay or go was a non-starter, because that's all they've been talking about since we met them, and of course they were going to stay. The whole point of it was to get Connie (Lauren Ridloff) trapped outside the gates when the Whisperers arrived, and there was probably a more interesting way to do that, if indeed it needed to happen at all, which remains to be seen. But all in all, it was a solid character-building episode.

The Walking Dead airs Sundays at 9/8c on AMC. Previous seasons are available to stream on Netflix.

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