John enters the battle scene with Eleanor, Arthur, the Bastard, and Hubert. John instructs Eleanor to stay behind in France to look after the English territories there. He assures Arthur that he will be in good company on a return to France, but he is sure his mother will grieve. John sends the Bastard before his party in order to collect the wealth of the monasteries.
John takes Hubert aside and thanks him for his loyal service. John says he wants to ask Hubert to do something, but says he changed his mind. Then he tries to ask him again and stops himself. Hubert assures the king that he loves him well enough to do anything he asks. John points out Arthur, saying he is a serpent who stands in his way. John reminds Hubert is Arthur's keeper. Hubert says he will keep him out of the king's way, but John suggests sending him to his grave might work best toward that end. Hubert says Arthur will not live. John is pleased, bids farewell to his mother, and sets off for England.
Philip enters with Louis and Pandolf. Philip remarks on a storm, saying that it has destroyed his entire fleet. Pandolf encourages him, but Philip insists that he has lost; Angers has been lost, Arthur has been captured, and the English have returned to England.
Constance enters with wild hair and a distracted appearance. She remarks on the unfortunate end of Philip's peace with John, and calls mournfully for death. Philip tries to soothe her, but she continues. Pandolf says she suffers from madness, not sorrow, but Constance disagrees. She was wife and mother to heirs to the English throne, she declares, and yet her son is now lost. She says she wishes she were mad so she could forget her son; being left in command of her reason, she can only imagine suicide as an end to her woes. Philip urges her to pull herself together, which she begins to do as she speaks to Pandolf about seeing her son again in heaven. As she remembers her son, she despairs, and exits, followed by Philip.
Louis now expresses his own woe, saying nothing in the world can bring him joy again. Pandolf urges him to consider the losses of the day as a mere bad symptom on the way to health. Pandolf prophecies discord in England; John may have Arthur, but he won't have civic peace, and he will have to continue to defend his kingdom. He predicts that John will have to kill Arthur. Louis asks how he may benefit from Arthur's death, and Pandolf reminds him that with Blanche as his wife, he can make the same claim to the throne that Arthur had.
Louis continues to despair. Pandolf remarks that when John kills Arthur, his citizens will be appalled and will turn against John, welcoming a change in ruler in the person of Louis. Louis is unconvinced, so Pandolf adds that the people will be enraged at reports of the Bastard stealing from monasteries. Pandolf is delighted with the opportunities provided by unrest in England and urges Louis to go to Philip and plan an assault.