
S01E01 Fermat’s Last Theorem
At Asung High, Yoon Su’s new workplace, she gives a tricky question for students who want to join the math club. While no one in the class got the question right, a correct answer sheet...
Seung Yoo and Yoon Su finally reveal the truth behind the scandal that happened in their past. While Noh Jung Ah puts forward a scapegoat after getting cornered, Ye Rin begins to crumble in her anxiety and despair. Meanwhile, Yoon Su, who now can smile like Seung Yoo always wanted, chooses to be in the position to protect Seung Yoo.
A sexual scandal between a math teacher and a student in a prestigious high school ended in tragedy. 4 years later they meet again, now as adults, to reveal the corruptions in school and to regain one's reputation as a teacher.