This chapter opens with a discussion between King Henry IV and his son-in-law, the Duke of Cambridge. The Duke is concerned about his son's health and wants to make sure that he is well enough to take part in the battle. He is also concerned about the fact that his father, the King, has ordered him to garrison the borders of England and France so that he will be able to perform his duties as a royal prince. He tells his son that if he dies in battle it will be worthy of his title as a prince and will make him the heir to the throne of England. He also tells him that he has a potion that can make him strong in short periods of time without any appearance or appearance , and that he can use it to make himself strong in the short time he is bedridden with poison. He says that if the enemy forces him to fight, he will die a worthy death