During fourth period, high schooler Da-jeong finds her classmate Tae-gyu dead in a classroom and Jeong-hun standing in front of him with blood on his clothes. In order to stop Jeong-hun from becoming the prime suspect, Da-jeong must help him find the real murderer, who is still inside the school building, under 40 minutes before period four ends.

Genres

Cast

Yoo Seung-ho

Han Jung-hoon

Kang So-ra

Lee Da-jeong

Jeong Seok-yong

Kang Gook-man

Park Cheol-min

Crazy

Rie Young-zin

Yun Sang-mi

Jo Yoon-hee

Hong Ju-hee

Min Kyung-jin

Headmaster

Im Soo-hyang

Fan

Kim Young-woong

History teacher

Jung Young-ki

Student in Grade 2 Class 5

Oh Jin-ha

Student in Grade 2 Class 5

Choi Hong-rak

Student in Grade 2 Class 5