A coup in North Korea forces an agent to defect to South with unconscious "Number One". While operatives from North hunt for both of them, the agent has to work with South Koreans to stop the nuclear war.
|郑雨盛 (Woo-sung Jung)||饰||Eom Chul-woo|
|郭度沅 (Do-won Kwak)||饰||Kwak Chul-woo|
|金甲洙 (Kap-su Kim)||饰||Ri Tai-han|
|金义城 (Eui-sung Kim)||饰||Lee Eui-sung|
|李璟荣 (Kyeong-yeong Lee)||饰||Kim Kyeong-yeong|
|出品公司||YWorks Entertainment (presents)|
|发行公司||Sega Sammy Entertainment (2017) (Theatrical) (South Korea)|
|Next Entertainment World (2017) (Theatrical) (South Korea)|
|Netflix (2018) (Video) (Argentina)|
|Netflix (2018) (Video) (Singapore)|
|Netflix (2018) (Video) (World-wide)|
- The shared name of the two main characters, Chul-woo, is a homophone for 'Steel Rain' in Korean hanja - 'chul' can stand for 'steel' or 'iron', while 'woo' can mean 'rain' or 'rainfall'.