I definitely feel that Act Three determines, rather obviously, the course of the remaining story. Hamlet is completely beside himself with doubt, grief, and anger. He is craving knowledge about death, the afterlife, and his father's murder. He wants to kill Claudius, but doesn't want to do it while he's praying. This shows that Hamlet wants truth about the afterlife because he wants to make sure that even after Claudius is dead, he's suffering. That shows that Hamlet really has it in for this guy. The scene in which he confronts his mother is definitely the climactic foreshadowing of the play. He is losing it...there are so many things he wants to know yet cannot know and its pushing him to practical insanity. Everyone and everything is unraveling at a rapid pace. Nobody has any control. By accidentally killing Polonius the audience can see now how unpredictable the events are becoming, and how unpredictable Hamlet has become. Is Hamlet going to get his revenge? Or is he going to kill himself? Or is he even going to kill Claudius? These are all questions I believe readers could wonder while reading this Act. All in all, darkness is looming over Denmark, and it's only a matter of time. Dun dun.