Lee Bum Soo's secret identity has been revealed.

During the 8th episode of the KBS drama "IRIS 2" that aired March 7, Yoo Joong Won (Lee Bum Soo) is exposed of his real identity.

Yoo Joong Won aims his gun at Park Cheol Young (Kim Seung Woo). Park Cheol Young says, "Why are you doing this?" and hesitates. Yoo Joong Won says, "Thank you for everything" and shoots. Yoo Joong Won stares at Park Cheol Young's dead body and says, "I betrayed my country? I never threw out my country. My country is just different from your country."

Soon after, Joo Joong Won meets up with the other team members as if nothing happened. He then hands them a cellphone with a footage of IRIS shooting. Yoo Joong Won adds, "Did he get shot?" and pretends to be shocked. All team members are fooled by his act and says, "He told us to give this to you in case something bad happens" and hands him a key.

The key opened a safe that held cash, passport, gun, cellphone and etc. Yoo Joong Won takes everything and makes a phone call. He says, "Assignment complete. I'll be back." In the following scene, he appears wearing the uniform of a North Korean soldier. He was reminiscing about the past.

Yoo Joong Won began to despise South Korea when his little sister died. He then pretended to be a North Korean refugee and approached Park Cheol Young.