Kang soon suspects things are not as they seem and discovers that the students, (both boys and girls) are being abused by the principal (a powerful and highly respected member of the community), an administrative head and a dormitory superintendent.
Kang's efforts to bring the crimes to the attention of the public are met with resistance by corrupt police, doctors and other business leaders.
When the case comes to trial, the defense lawyers further attempt to discredit Kang by bringing to light his past misdeeds, including the affair with his former student who committed suicide.
Kang, humiliated at having his personal failures publicized and frustrated by the lack of justice, decides to leave Mujin and return to his family in Seoul.
[2] A film adaptation also titled The Crucible (Korean: 도가니; RR: Do-ga-ni), was released in 2011 starring Gong Yoo as Kang In-ho and Jung Yu-mi as Seo Yoo-jin.