In the sixth episode of "His & Hers," Anna narrates that if you're going to do something, you should do it well. This principle applies to killing as well.
Lexy, whose middle name is Alexis, is introduced as Catherine's older sister. In a flashback, we see the Kelly family at the lake house, where Andrea, their mean-spirited older child, bullies Catherine. Lexy empties Andrea's inhaler during a boat ride, resulting in Andrea's suffocation and death in the middle of the lake.
Richard and Lexy later attack Anna for various reasons. Richard overhears Anna calling Jack to inform him that Lexy and he are the killers, and he becomes enraged. He accuses Anna of being a manipulator who ruins people's lives for her own gain. Anna defends herself by shooting Richard with her gun but locks him in the cellar instead of injuring him. Lexy arrives and attacks Anna, furious that she tried to harm her husband.
Lexy's involvement in the plot is exposed when Sheriff Barnes calls Priya to inform her that Duffie has confessed that Lexy told Rachel about Andrea's death and that Rachel and Helen blackmailed Lexy about it. This explains why Lexy slapped Rachel. The scene ends with Lexy grabbing Anna's empty gun and pulling the trigger, just as Jack and Priya arrive at the lake house. Jack puts himself in front of Anna to protect her, while Priya kills Lexy.
The cops find Rachel's nails and the murder weapon at the lake house, and Richard is arrested as an accomplice. Sheriff Barnes recalls seeing Lexy crying in public and celebrating in private after Andrea's death. Anna apologizes to Jack for not telling him sooner about Lexy's attack at her Sweet 16, and Priya feels guilty about killing a technically unarmed Lexy. Jack reassures her that she will be okay.
In the aftermath, a year passes by swiftly. Anna, now pregnant with Jack's child, returns to her role as a TV anchor. Richard's lawyer asserts that he never intended to kill Anna and that he and Lexy merely wanted to frame her for the murders. Anna is suing him, and his people are eager to settle. Her new agent uses intimidation to convince Jim and the network to offer her a lucrative contract. Meg accepts Anna and Alice as family, and Anna hires a nurse to care for Alice.
Jack, Anna, and Meg visit Charlotte's grave, followed by a visit with Alice. While Jack and Alice play with Meg, Anna discovers a letter from her mother. The letter reveals that Alice is the real killer, and her motivations are revealed through the letter's contents.
Flashbacks show that Charlotte died of crib death, and when Anna ran away, Alice watched her old tapes to feel closer to her. When she reached the Sweet 16 tape, she saw that the boys didn't actually rape Catherine but that Anna had dropped her handicam (which was still recording) to push them off Catherine. The boys decided to rape Anna instead, and she begged Catherine for help, but Catherine ran away. Helen, Zoe, and Rachel just laughed.
Another flashback shows Catherine being mean to Alice, who used to be her maid. When Lexy took Anna's job, Alice immediately recognized her. Alice often visited Charlotte's grave and learned of Rachel and Jack's affair there. On Charlotte's death anniversary, Alice saw Anna return and spotted Jack and Rachel together. That's when she decided to avenge Anna by pretending to have memory problems.
She slashes Rachel's tire, kills her, ditches her clothes, and pretends to be a senile woman, bringing Anna back home to her. As a former cleaner, she has keys to most places like the school and Zoe's house. She kills Helen to reconcile Jack and Anna and kills Zoe to give Anna a child - Meg. She frames all the murders so it looks like Lexy is the killer. She never meant for Lexy to die but for her to be imprisoned for abandoning Anna. This is why she plants Rachel's nails and murder weapons at Lexy's lake house. She also cancels the hotel reservation, confident that Jack will save Anna from Lexy and Richard at the lake house. However, she doesn't care that Priya killed Lexy.
When Anna reads Alice's confession, she smiles because Alice ends the letter by hoping that Anna loves her children the way she loves Anna. Anna's face transforms from shock to a smirk as she processes that her mother has avenged her.
