- Some people may think that mercy shouldn't be a part of justice, but our narrator disagrees and doesn't think they have to be irreconcilable.
- All of Mercilla's subjects think she's a very just and merciful queen, and Arthur, Artegall and everyone else is convinced that Duessa is guilty and should be punished (although we never actually hear what that punishment is).
- After the Duessa trial, Artegall and Arthur stay longer at Mercilla's court enjoying the queen's company.
- One day young men come to the court to ask for help for their mother, whose land has been invaded by a terrible tyrant.
- The mother's name is Belgae, and she had been a great lady with seventeen children before this tyrant had killed twelve of them and left only five.
- This tyrant was a kind of monster with six arms and six legs who was believed to be the son of giant and from a family of purple people.
- The tyrant was called Geryonco and he fled to Belgae's land after his father had been killed.
- Since she had recently been widowed, Geryonco convinced Belgae to trust him, since she needed help, and eventually gave him the power to rule.
- Once he gained power, he became a terrible ruler, giving up her children one by one to a monster and oppressing the land.
- So her last two sons had come to Mercilla for help, and Arthur asks the queen if he can go with them to help.
- The queen agrees and Arthur goes off on his quest, leaving Artegall to go off on his own quest himself.
- Soon Arthur arrives at the land of Belgae, and he finds her hiding from the tyrant alone in the wilderness.
- She is overjoyed when she sees her two sons coming toward her and thanks Arthur greatly for coming to their aid.
- Arthur feels bad to see her in this sad state and comforts her and urges her to go somewhere more comfortable.
- She replies that she has nowhere to go that isn't under the tyrant's power, but Arthur promises that they will find somewhere or he'll force somewhere to take them.
- They arrive soon at a city that used to be the queen's until it was taken over by the tyrant.
- He built a luxurious chapel in front of the city's castle dedicated to his idolatrous religious beliefs.
- Underneath the altar of that chapel lurks a horrendous monster and the chapel is guarded by a fearsome soldier.
- Although Belgae tries to dissuade him, Arthur rides up the castle and calls upon the guard, who rides up to fight.
- They begin fighting and Arthur ultimately triumphs, stabbing the solider right through his shield.
- Three other knights then ride up to challenge him as well, but after Arthur handily dispatches one of them, the other two flee in terror.
- Arthur follows them and kills them both, finally winning entrance into the castle since none of the other residents are brave enough to face him.
- And so Arthur triumphantly leads Belgae and her sons into the castle.