Possible Clues:

• When Prospero says, 'We are such stuff as dreams are made on'
• End of ''Aida''
• ''La Bohème'' finale
• When Rosencrantz and Guildenstern are last seen in "Hamlet"
• When Rosencrantz and Guildenstern are last seen in 'Hamlet'
• When the "Macbeth" witches add "eye of newt"
• When the 'Macbeth' witches add 'eye of newt'
• Last part of a play, perhaps
• When Antony dies in 'Antony and Cleopatra'