Tormented by her high school classmates and with nowhere to turn for help, Moon Dongeun sinks into despair before deciding on a new mission in life.

With Park Yeonjin’s wedding on the way, Dongeun’s revenge rolls out according to plan. Meanwhile, a fateful encounter at a hospital takes place.

After securing the services of an amateur sleuth, Dongeun uncovers scandalous secrets that she leverages for the next phase of her scheme.

Already on edge over the past resurfacing, Yeonjin grows more anxious when she learns about her daughter's new homeroom teacher — and of a sudden death.

While Ha Doyeong comes across an intriguing game opponent, Yeonjin realizes her deepest secrets are at stake when she tries to intimidate Dongeun.

Son Myeongo's sudden absence causes tension in the friend group. Dongeun finds her trust in Kang Hyeonnam tested.

Dongeun shares her traumatic past with Joo Yeojeong, who has unfinished business of his own. A new plan is put in place for Hyeonnam’s daughter.

Questions arise over Myeongo, Dongeun gives Yeonjin a chance to come clean about her past, and the circumstances of Yoon Sohee's death are revealed.

Yeonjin threatens Hyeonnam after discovering her involvement with Dongeun. Yeojeong devises a way to get the truth out of Yeonjin.

Hyejeong finds an incriminating recording on Myeongo's tablet, and Hyeonnam receives an unwelcome visitor as she prepares to send her daughter abroad.

Dongeun's end game comes into focus as she sends Jeon Jaejoon a troubling package and orchestrates a plan to take down Yeonjin and Lee Sara.

As Sara and Yeonjin deal with the aftermath of their crumbling reputations, Dongeun learns the details behind Yeojeong's private struggles.

Yeonjin and Shin Youngjoon panic over Myeongo. Dongeun takes care of a lingering problem. Yeonjin’s mother schemes to remove a threat.

Doyeong issues an ultimatum. Dongeun demands a piece of evidence be handed over. Yeonjin attempts to do damage control after old videos appear online.

As the final pieces of Dongeun's revenge plot slot into place, she considers what comes next — and what it will mean for Yeojeong.