The old detective (Samuel L. Jackson) leads the detective (Chris Rock) to investigate the brutal serial murders. The rumor that the "Jigsaw Killer" has returned to the underworld has once again aroused the fear in everyone's heart. This time, the new rules of the game seem to be directed at the police. The "death vortex" left at each murder scene will drag them into a bloody abyss that is difficult to extricate... The ninth part of "Saw" was written by the two screenwriters of the eighth part, Pete Goldfinger and Josh Stolberg. Darren Lynn Bousman, who directed "Saw 234", returned to direct this time.