Salisbury, Pembroke, and Bigot meet on the field, astonished that King John's forces have proven to be so powerful. Count Melun, a French nobleman, enters; he is wounded, and he urges the English lords to turn back from the path of their rebellion and seek out John to plead for his mercy. Melun reports that if the French win that day, Louis has ordered the English lords to be beheaded. The English are astonished, but Melun insists that he is telling the truth; he will die soon and has no reason to deceive them. Salisbury believes Melun and thanks him. He urges his companions to return to John.
Louis enters, remarking on the strength of the English army. A messenger arrives to report the death of Melun, the departure of the English lords, and the sinking of his army of reinforcements. Louis is dismayed at the news; with his reinforcements annihilated, his chances of victory are now very slim indeed.
Hubert and the Bastard encounter each other in the darkness. Hubert reports that the king has been poisoned by a monk. He adds that the English lords have returned to John, bringing his son Prince Henry. The Bastard replies that he has lost his men, who were drowned in the rising tide on the flatlands that night. He asks Hubert to escort him to the king's side.
Prince Henry discusses his father's health with Salisbury and Bigot. Pembroke reports that John can still speak. Henry mourns the fact that his father's mind has been destroyed by the sickness, even while his body still seems in good health. John is brought in, babbling. He tells Henry that he has been poisoned. The Bastard arrives, and he reports that Louis approaches unimpeded because the Bastard's forces have drowned.
King John dies. Henry marvels at the transitive nature of the world, where what was once a king can become a meaningless pile of dust. The Bastard swears to avenge the king's death, and turning to the lords, orders them to assemble their forces to help repel the French from their land. Salisbury reports that Pandolf recently visited them with an offer of peace from the Dauphin. The Bastard wants to attack anyway, but Salisbury says the peace has been agreed upon.
They discuss John's burial, and the Bastard swears to serve Henry. The other lords follow suit. The Bastard speaks of the suffering they have endured and comments that England has never been in danger of being conquered, except when it was divided against itself. Now that the lords have returned to the allegiance of their English king, England is strong again. Nothing can weaken England if its citizens remain loyal, he says.