"O from this time forth my thoughts be bloody or be nothing worth."
Queen Gertrude tells King Claudius that Hamlet has gone mad and killed Polonius. Act 4, Scenes 1-2
Claudius sends Rosencrantz and Guildenstern to get Hamlet but they're unable to. Claudius decides to send Hamlet off to England. Act 4, Scene 3
Hamlet talks about everything that's happened and that he will shed blood if he has to, to succeed in his mission to get revenge on King Claudius. "O from this time forth my thoughts be bloody or be nothing worth." Act 4, Scene 4, Lines 68-69