Possible Clues:

• When Portia says, "The quality of mercy is not strained"
• When Ophelia drowns, in "Hamlet"
• Penultimate part of ''Hamlet''
• 'Double, double toil and trouble' time
• Juliet drinks the poison in it
• Chekhov play ending, often
• When Otello dies
• When Brutus sees Caesar's ghost
• When Antony says 'I am dying, Egypt, dying'
• When Carmen dies