But his flawed heart,
Alack, too weak the conflict to support
‘Twixt two extremes of passion, joy and grief,
Burst smilingly.

– William Shakespeare

King Lear, Act 5, Scene 3. Edgar describes the death of his father Gloucester, who dies of shock when his estranged son finally takes off the mask and reveals himself to him. The conflicting emotions of happiness and sorrow prove too much for Gloucester and his heart bursts. He dies of heartbreak, as will Lear. But his last breaths are filled with the knowledge of his son Edgar’s love.