In need of a caregiver for her ailing and very wealthy father-in-law, Woo A-jin hires Park Bok-ja, a woman who's not as honest as she seems.
Ju-mi is adamant about firing Bok-ja, but A-jin knows how much Bok-ja means to her father-in-law. Plus, Bok-ja is already ahead of the game.
Feeling doubtful about Bok-ja, A-jin decides to redo her background check. Meanwhile, A-jin's husband, Jae-seok, begins a "morning exercise" routine.
Now that even A-jin has turned against her, Bok-ja schemes to make the best of Chairman Ahn's upcoming birthday party to secure her stay.
A-jin asks Bok-ja to leave now that the birthday celebration is over. But Bok-ja refuses, saying she'll answer only to Chairman Ahn.
Chairman Ahn's shocking announcement catches everyone off guard. A-jin begins to suspect that Jae-seok may not be exercising after all.
Chairman Ahn entrusts A-jin with planning his wedding. To Ju-mi and Jae-hui, who are still against the marriage, A-jin confides that she has an idea.
Despite A-jin's warnings, Jae-seok can't stop thinking about Seong-hui. Bok-ja forges ahead with her scheme to obtain control over the household.
A-jin decides to visit Seong-hui at her apartment. Sensing that something is troubling A-jin, Bok-ja resolves to find out what's going on.
A-jin notifies Bok-ja of her plan to move out and hands over the household responsibilities. Jae-seok presents Seong-hui with a new place to live.
Seong-hui asks Jae-seok to put the house under her name so A-jin can't move in. Chairman Ahn seeks A-jin's advice when crisis hits Jae-seok's company.
Undeterred by Seong-hui, A-jin proceeds to move into the home she bought with Jae-seok. Meanwhile, A-jin's mom finds out about A-jin's troubles.
Taking the advice of a CEO, Bok-ja cuts ties that could get in the way of her success. Ju-mi asks A-jin to help her husband get out of jail.
Taking up Mr. Han's offer, Bok-ja prepares to sell her shares to his fund group. Meanwhile, Chairman Ahn learns the truth about Bok-ja's past.
When Bok-ja disappears after causing chaos at the company, the three Ahn siblings and Ju-mi become desperate to find her.
A-jin launches a plan to make a living for herself and Ji-hu. Though she's no longer a part of the Ahn family, she promises to make Bok-ja come back.
Gi-ho reveals his feelings for A-jin. Pung-suk gets visited by the National Tax Service. Jae-hui takes Mr. Han's advice to get her dad's company back.
The detectives work on two cases involving the Ahn family: a missing person and a theft. Bok-ja finally checks out of her hotel suite.
A-jin and Jae-seok are the only two with solid alibis. The remaining suspects' possible motives and whereabouts on that night slowly come to light.
Someone appears at the police station claiming to be the killer. A-jin finds closure from her past way of life and begins a new journey.
