After a tumultuous marriage and a secretive divorce, Han Ji-eun, a talented florist in Seoul, finally finds balance when she shares custody of her daughter, Hye-rin, with her ex-husband, Kang Min-ho, a renowned and controlling surgeon. However, her peace is shattered when her first love, Seo Jun-won, unexpectedly reappears, bringing with him not only feelings from the past, but also a dangerous secret that could change everything. Jun-won, now an elite criminal investigator, is involved in a case that seems to revolve around Ji-eun and Min-ho. As mysteries emerge, Ji-eun realizes that her life is intertwined with a conspiracy greater than she imagined. Between silent threats, stalking and lies, she must decide who to trust. But when secrets from the past come to light, her decision could be a matter of life or death.