Korean, police corruption, internal affairs, craziness. The violence is somewhat less graphic than usual, with no blood sprays. What's become of the genre? The structure is completely standard, so it comes down to the particularity of the McGuffins; some are pretty funny, others totally stock. I guess this is some proof that convoluted whodunnits can survive in the age of the mobile phone. Cho Jin-woong does well as the bad dude.