The opening flashback shows that Colonel Han's return to the military was actually relatively recent. Hardly six months ago he was still Director Han, working in the private sector. More disturbingly, this flashback makes it clear that Colonel Han has always known that madness rabies derives from the Next drug. Despite this clear indicator of the disease's origins, neither Colonel Han nor anyone else can do very much when it comes to proactively using this knowledge to contain outbreaks, Happiness - Drama, Ahn Gil-ho, Han Hyo-joo, Han Sang-woon, Jo Woo-jin, Kang Ji-eun-I, Lee Joon-hyuk-I, Park Hyung-sik, Park Joo-hee