Edmund calls for his officers to lock up Lear and Cordelia. She tells her father 'We are not the first / Who with best meaning have incurred the worst' and he tells her they will live together in prison 'As if we were God's spies' hearing 'poor rogues / Talk of court news'. Edmund secretly sends his captain after them with a note to ensure that they are both put to death, telling the captain 'to be tender-minded / Does not become a sword.'
Albany enters followed by Regan and Goneril who argue over Edmund's position. Regan announces her intention to make Edmund her 'lord and master'. Regan also begins to feel very ill and Goneril admits to the audience she has poisoned her sister.
Albany has Edmund arrested for 'capital treason', and calls Goneril a 'gilded serpent' for her betrayal in promising to marry Edmund if he kills her husband. A trumpet sounds and Edgar steps forward, in armour which hides his face. Edgar publicly accuses Edmund of being a traitor. Edmund and Edgar fight and Edmund is defeated. Edmund admits 'What you have charged me with, that have I done, / And more, much more'.
Edgar reveals who he is really is and how he disguised himself as 'Poor Tom' and looked after his blinded father. Edgar describes how he finally told his father everything and 'asked his blessing' to fight this duel with Edmund but that ''Twixt two extremes of passion, joy and grief' Gloucester's heart 'Burst smilingly' and he died. Listening to this as he dies, Edmund says 'This speech of yours hath moved me, / And shall perchance do good' but they are interrupted by a gentleman who runs on with a bloody knife taken from Goneril's heart and tells Albany that Goneril died after confessing that 'her sister / By her is poisoned'.
Kent arrives dressed as himself again. Alb