Watch VoirFilms. This making-of is made up of a series of short vignettes, starting with a piece on Shin Ha-Kyun and Bae Du-Na learning sign language for their roles, followed by some on-set interviews with Song Kang-Ho, Shin, and Bae. One of the noteworthy takeaways from these clips is the oddly frequent laughter on the set, especially while shooting some particularly wrenching scenes. Next are a few pieces on the prosthetic effects used for some of the stabbings, etc. It wraps up with Park Chan-Wook discussing the casting process for some of the smaller roles and footage of Park's friend Ryu Seung-Wan helping to choreograph a scene on set.