Claudius tries to bait Hamlet into duelling him, but he refuses to bite until Claudius insults the woman whose favour he wears - unbeknownst to him, Ophelia - at which point Hamlet draws his sword and soundly beats his uncle to the ground. Claudius only defeats him by attacking him from behind when he's not expecting it and even then Hamlet is graceful in defeat, remarking that he prefers to use his mind as a weapon.
After spending almost the entire film being mocked and sneered at by the other ladies, though especially Cristiana, and never retaliating, Ophelia finally has enough when Cristiana tauntingly tells her that Hamlet was murdered en-route to England on the orders of Claudius. She tackles her to the ground and nearly chokes her with her arm, ordering her to tell her what she knows "or I swear I'll...". She doesn't get to finish, as the threat is clear enough to make Cristiana cough up the truth.
The film manages to turn Ophelia's descent into 'madness' and apparent suicide into one long "Moment of Awesome". After finding out Hamlet is still alive and figuring out that Claudius was the one who betrayed Mechtild, Ophelia knees her scumbag fiance in the groin and smashes him over the head with a torch to escape. She then bursts into the throne room and acts like a complete lunatic, doing everything she can to make it convincing to everyone present. At the same time, she uses her 'babbling' to subtly hint to Horatio that she intends to fake her death and he needs to dig her up after she's buried, as well as tip off Gertrude that Claudius is not the man she thinks he is and screwed over her sister. Upon approaching Claudius, she speaks to him with barely contained disgust, slams her flowers down in front of him and gets a decent Take That!: "Here's fennel, for you And colombine, for flattery. You'll miss it now my father's gone." they both know she's faking her madness and that she knows the truth, but he's unable to do anything because everyone else sees her as an innocent girl who has lost her mind to grief and he'll look like an utter jerk; she even gives him a cheerful grin right after insulting him. Ophelia then proceeds to sprint to the nearby river and drinks snake venom before flinging herself in the water; she knows the poison could easily kill her or that she might actually drown before anyone gets to her, but takes a gamble to pass herself off as dead, Juliet-style, in order to escape and try to help Hamlet.
Upon finally realising what Claudius really is and seeing her son die in front of her because of his actions, Gertrude grabs Hamlet's sword and stabs an unwitting Claudius through the chest, hard enough that the blade goes right through Claudius and the back of the throne.
