S1, E1: Four friends entangled in dangerous relationships Se-yeon, Eun-soo, Jeong-won, and Hwa-young. 2 years after her husband's death, Se-yeon lives quietly with her daughteruntil her peace is disturbed by anonymous calls. Psychiatrist Eun-soo offers sincere advice as Jeong-won struggles with anger issues. Meanwhile, following a client's husband, Hwa-young unexpectedly encounters someone shocking…