Act 4, Scene 5

Ophelia is not well. A gentleman reveals to Gertrude and Horatio that she has been wandering around, talking nonsense and singing songs. Just then, Ophelia enters, acting utterly insane. She sings songs about death, love, and flowers. Gertrude can make neither heads nor tails of what she’s saying, but Ophelia’s songs hint at Hamlet’s betrayal and her father’s death. After she leaves, Laertes returns, demanding to know where his father is. Claudius informs Laertes that Polonius is dead but swears it wasn’t his fault. Ophelia reenters, talking and singing nonsense again. Laertes is horrified to see his sister in such a state, and he vows revenge on his father’s killer and his sister’s persecutor.