there should be another category to describe film that do not exactly fit the accepted genre of horror and supernatural or psychological thriller . i call it the puzzle box genre . puzzle box film challenge you to think and discover the answer and rather than spoon feed them to you . not everyone enjoy that when go to the movie . classify a film a a puzzle box would make it easy for that film to find it audience . the i inside be one of those film . others be mulholland drive and identity ( same writer a the i inside ) and jacob ladder and and many modern korean film and such a oldboy and hypnotize and tale of two sister and and the brilliant but obscure spider forest . and to a less extent and memento and which be fun on the first watch and but bore me on the second and since no new clue be reveal . the i inside give more answer at the end than oldboy or mulholland drive and but it be still a fascinating film . this be be ryan phillippe most challenging role and and he do an excellent job and but the standout for me be piper perabo she go through some tricky personality quirk ( i be purposely leaving thing vague ) which add to the mystery .