The setting is Gloucester's castle, where Gloucester and Edmund are conversing. Gloucester tells his son that when he asked Regan and Cornwall to leave, so that he might offer aid to Lear, they seized his house. Now Gloucester is little more than a prisoner in his own home, forbidden to even speak to the king. Gloucester also tells Edmund that he has heard of a plan to revenge the king's injuries, unaware that he is divulging the plans to a traitor. Gloucester exits. Alone, Edmund plans to gain Cornwall's favor by revealing the plan to aid the king.
At the beginning of the play, Gloucester appears weak and foolish, easily fooled by Edmund. In Act I, his boasts about easy conquests misleads the audience into dismissing Gloucester as a silly old man; but in this scene, the earl seems worthy of the king's allegiance. Gloucester proves that he is willing to sacrifice his own life for the king by disobeying Regan and Cornwall. This genuinely heroic behavior sets Gloucester apart from Edmund. An opportunist, Edmund takes advantage of his father's trust, seizing the chance to win Cornwall's favor. Betraying his father will provide Edmund with the position and wealth he craves. Acting without hesitation, Edmund sets out on a course that belies his breeding; a triumph of conscience is not a likely prospect in his unfolding treachery.