They Messed with the Wrong Sister

Episode 1

Carla Holt is the kind of sister who puts her twin brother Zach above everything—she even gave him her bone marrow when he was sick with leukemia, and she made the family keep it a secret so he'd never feel guilty. So when Zach finally brings a girlfriend home, Carla goes all out: no spicy dishes, everything prepared just right. Then Mary Cohen walks in the door, and the warm welcome curdles fast. Mary is already dreaming out loud about marrying into a wealthy family. Carla has no idea what's about to land on her.

Episode 2

The first dinner turns into a minefield. Mary looks around the Holt mansion like she's already claiming it, telling Anna that once she marries Zach, she'll be set for life—and that Carla clearly doesn't like her. So Mary decides she'll make Carla accept her. At the table, Zach peels shrimp for Carla, and Mary's temper snaps. She needles Carla, mocking her age and her single status, and Carla bites her tongue only for Zach's sake. It's the first real crack in the family's shiny surface, and Mary is the one holding the hammer.

Episode 3

Mary pushes harder, acting like the lady of the house and demanding to be served. She sneers at Carla for being lazy and single, then offers to "set her up" with her cousin—a jab meant to humiliate. Carla fires back that she'll be running this family soon enough. The insults escalate until Carla has had enough of being disrespected in her own home. Mary's mask slips: she's not the timid, sensitive girl Zach described. She's calculating, and she's testing exactly how far she can push before someone stops her.

Episode 4

Carla slaps Mary, and the house erupts. Zach rushes out to find his girlfriend in tears, and Mary spins the story—she was only trying to help, and Carla attacked her. Mary demands that the "lunatic" be thrown out, but the servant Elmer reminds everyone who actually makes the rules in the Holt family. Mary plays the wounded outsider, claiming she didn't know any better and was just raised differently. Zach begs Carla to let it go and promises to straighten Mary out. Carla gives her one last chance—but warns Zach to keep Mary away from her until she learns some respect.

Episode 5

Carla's fiancé Cyril Cahill shows up, and the mood shifts. He's the owner of Cahill Group, and he's brought her a gift: a limited-edition necklace designed by a jewelry brand under his company, made just for her. Talk turns to whether Zach should take over more responsibility, but Carla worries about his health and knows their parents won't agree. The two tease each other about marriage. But the necklace—Carla's most precious token from him—is about to become the center of a very ugly storm.

Episode 6

Carla wakes to find her necklace gone. Elmer confirms Zach brought Mary upstairs the day before, and the security footage proves it: Mary took it. Then Mary goes live wearing Carla's one-of-a-kind necklace, bragging to her followers and promising to give one away. Carla is furious—this is theft, and a hard childhood is no excuse. But when she threatens to call the cops, Zach begs her not to, and lets slip the lie that's been poisoning everything: he believes Mary is the one who donated bone marrow and saved his life. Carla freezes. She knows exactly who the donor was.

Episode 7

Mary's live stream continues from inside Carla's own house, and she's milking every second of it—showing off the mansion, the wine flown in from France, the closet full of tagged clothes. Anna joins the fantasy, already planning how Carla will marry Anna's son Jack so the house falls into their hands. Mary vows to make sure Carla ends up in Jack's bed, forcing a marriage. Then Carla walks in on the whole performance and demands to know who gave Mary permission to play lady of the house in her home.

Episode 8

Carla lays down the law: she bought this mansion with her own money, not the Holt family's, and Mary is going to hand back the necklace and get out. Mary refuses, claiming everything the Holts own will be hers once she marries Zach. Carla also throws the bone marrow lie in her face. Mary's relatives pile in, calling Carla shameless and threatening her for "seeing another man" while supposedly promised to Jack. Carla stands her ground and calls Mary exactly what she is—a parasite who moved her whole family into someone else's house.

Episode 9

Cyril can't reach Carla, and Elmer tells him she went to the new house—so he heads after her. Inside, Anna and Mary corner Carla, bragging that Jack works at Cahill Group and is about to make team lead, so Carla should feel honored to marry him. Carla coolly informs them she could have Jack fired with a single phone call—even if he were a vice president. Anna lunges at her, and Carla hits back. Then Zach calls Mary, suspicious because her car is still outside. Anna orders Carla dragged into the bedroom as Zach closes in.

Episode 10

Zach arrives to chaos: Anna and Mary claim they're just "teaching Carla a lesson" for cheating, and Jack decides his arranged bride is hot enough to keep—then tries to force himself on her. Carla warns him that her fiancé owns Cahill Group and he'll be fired, but Jack doesn't believe her and moves in anyway. Carla fights him off. Meanwhile, Mary keeps Zach distracted downstairs, lying about the necklace and sending him out for cake so he won't hear the struggle above. Carla is cornered, outnumbered, and running out of time—but she hasn't stopped fighting.

Carla's not the helpless sister they counted on, and the people who crossed her are about to find out exactly who they messed with.