OCN's upcoming thriller "The Voice," which tells the story of police call center agents played by Jang Hyuk (Beautiful Mind) and Lee Hana (Unkind Woman, both of which lost their parents by a killer still on the loose. Just to get into their roles for police call center dispatchers and get used to with the environment, Lee Hana, and Yesung stopped by an Emergency call center in Incheon.

Written by Ma Jin-won (I Am Legend) and directed by PD Kim Do-hyuk (I Love Lee Taeri), The Voice seems to be a dark and frightening for the fans. 

Lee Hana playing the role of Kang Kwon-Joo who is a brilliant voice profiler with an extremely acute sense of hearing and who leads the team of Emergency Call Center's "Golden time team." She had lost her father. While Jang Hyuk's character Moo Jin-hyuk is a former star detective whose wife was murdered by a Serial killer who is now working as the first responder at the Call Center.

While Yesung's role is a brilliant young hacker and a very important member of the Golden Time Team. Two more actors added in the team are Baek Sung Hyun (Doctors) playing a detective named Shim Hyun-ho who reverses and actively helps his sunbae Jang Hyuk and Sohn-Eun-seo (Bring it on Ghost). Sohn is from a family of international airport police officers and speaks in a stiff manner, though she is delicate and timid at heart. 

Lee Hana and Yesung at the Incheon emergency call center spoke with the relationship manager and learned about the actual crime scenarios and how does the call center handles such kind of emergencies. They were taught about the emergency response manual used as standard operating guidelines.

OCN's voice will premiere in January 2017.