Ji-won attends an event with Ji-hyeok and meets someone who will be a future topic of discussion. Ji-hyuk becomes concerned as he observes Ji-won's transformation. After a heated encounter at the high school reunion, Su-min becomes even more obsessed with Ji-won. Meanwhile, as Ji-won tries to provoke Su-min with Min-hwan, she unexpectedly discovers a secret about Ji-hyuk during a work errand.