1.1 Gloucester and Kent, two powerful members of Lear's court, are discussing Lear's plans for dividing the kingdom. Gloucester introduces Kent to his illegitimate son, Edmund, and jokes awkwardly about banging Edmund's mother.
1.2 Edmund tricks Gloucester into thinking Edgar, his other son, is conspiring to kill him.
2.1 Gloucester comes in chasing Edgar, who Gloucester believes is guilty of plotting against him. Edgar escapes, but Gloucester announces that he is a criminal and puts a price on his head. He decides to give Edmund – his apparently good son – everything that once belonged to Edgar. Cornwall and Regan, who are now ruling the half of the kingdom Gloucester lives in, show up at his castle late at night. Gloucester has no choice but to welcome them in.
2.2 Gloucester protests when Cornwall wants to punish Lear's messenger, but Cornwall ignores him. Gloucester apologizes to the messenger, but he can't do anything since Cornwall is in charge. Later, Gloucester tries to calm down Lear, who wants to angrily confront Regan and Goneril for punishing his messenger. But Gloucester can't prevent the showdown between Lear and his daughters – nor can he stop Cornwall from ordering that Lear be locked out of the castle, even though it's a stormy night and he might get "hit in the face by lightning."
3.3 Gloucester tells Edmund that he's going to find Lear. He also confides in his son that he's received a politically dangerous letter about Cordelia's French armies coming to attack Cornwall.
3.4 Gloucester is shocked to find Lear outside in the rain – and hanging out with a smelly homeless man. He doesn't realize that this half-naked beggar is own his son, Edgar. Gloucester even complains to Kent about how much he's upset at Edgar's betrayal – with Edgar unseen right in front of him. Gloucester leads Lear, Kent, Lear's fool, and "Poor Tom" to shelter.
3.6 Gloucester brings Lear out of the rain and tells Lear and his followers to run away to Dover, since Lear's two older daughters are now plotting to kill him.
3.7 Meanwhile, Edmund has ratted out his father to Cornwall and Regan, and when Gloucester tries to come back home, he is arrested. He protests that they are his guests and therefore shouldn't be torturing him, because that's bad etiquette. Despite his protests, the duo has Gloucester tied up and pluck out his eyes. When Gloucester calls on his son, Edmund, to help him, Regan kindly informs Gloucester that it was Edmund who betrayed him in the first place.
4.1 One of Gloucester's old servants gives him some basic first aid and guides him out of the palace. Because Gloucester is now a traitor, it's a liability to be seen with him. So Gloucester tells the servant to go back to the castle and instead asks Poor Tom, who has no reputation to lose, to guide him to the cliffs of Dover. Gloucester, in despair, has decided to commit suicide.
4.6 Gloucester attempts to commit suicide, but doesn't realize he's actually just jumping onto some flat ground. So Gloucester lands with a little thump, alive, and Edgar, pretending to be another man, tells him he totally did fall of a cliff. After that miraculous rescue, Gloucester promises to stop thinking about suicide. Lear comes in and Gloucester recognizes his voice. Lear is clearly insane and Gloucester now feels twice as bad because the guy he always looked up to has fallen to a sad state. Once Lear leaves, Oswald, Goneril's messenger, enters and tries to kill Gloucester because there's now a price on his head. Edgar, still disguised, kills Oswald instead. All in all, Gloucester thinks it would be better to be mad like Lear and not have to deal with how bad their lives have become.
5.2 Edgar sticks Gloucester in a corner while he goes off to fight in the big battle where Goneril/Albany/Regan/Edmund square off against Lear/Cordelia/the French troops. Edgar and Lear's side loses. When Edgar goes back to tell his father this news, Gloucester starts leaning towards the suicide again as the best solution.
5.3 Edgar reveals that Gloucester died of a mixture of shock and joy (offstage) when Edgar finally revealed his true identity.