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.