An Yun Su works as an art teacher, living a peaceful, ordinary life, until it suddenly changes. Her husband is murdered, and she is accused of killing him. She struggles to clear herself of the murder charge. While in prison, she is approached by a mysterious woman named Mo Eun. Mo Eun is called a "witch" by the other prisoners because she can see through others and easily know what they think and feel. An Yun Su and Mo Eun both hold secrets, and they make a dangerous deal. Meanwhile, Baek Dong Hun is an earnest prosecutor respected by his fellow prosecutors. He maintains his composure in any circumstance and holds firm convictions. He digs into the secrets of An Yun Su and Mo Eun, risking his beliefs and honor. Jang Jeong Gu, An Yun Su’s lawyer, is a former boxer with a tenacious personality. He begins to pursue the truth to prove An Yun Su’s innocence.