Grieving the loss of a best friend she couldn’t protect, an ex-bodyguard sets out to fulfill her dear friend’s last wish: sweet revenge.

Woo-ri, 32, and Ja-young, 28, who both dislike being alone but have particular anxieties when it comes to dating, meet through an app.

Connected by phone in the same home but 20 years apart, a serial killer puts another woman’s past — and life — on the line to change her own fate.