Kent prepares to go to France to confront the king, and is mournful that Edward has banished him from his presence. Mortimer comes in disguised, having been freed. He asks if Edmund is going to France, and Kent says he is indeed.
The Queen cries to her son that all are cruel to her in France, and the prince suggests they return to England so he can win his father’s affection back quickly. The Queen sighs that such a plan will not work.
Sir John of Hainault joins them, and the Queen tells him how distressed she is. He asks them to come stay with the marquis, his brother. She agrees, hoping things will improve.
Kent and Mortimer enter, and the Queen is thrilled to see Mortimer alive. Mortimer says he has heard she has not been treated favorably, but he assures her that they have friends in England and they ought to retire there. Kent says it would be good if Edward righted himself and everything went back to normal, but Mortimer scoffs that Edward will not get rid of his flatterers.
Sir John suggests the men accompany the Queen to Hainault where they will find money and allies. The Prince is skeptical, but his mother hushes him.
Edward, Arundel, and Spencer Senior and Junior enter. Edward believes he has triumphed. He also is pleased to learn Isabella gets no aid from the lords of France.
A Post arrives with a letter for the Earl of Gloucester from Levune. Levune writes that he did what he was instructed to do with the French lords and now the Queen and Prince Edward, along with Kent and Mortimer, have gone to Hainault. They plan to give battle to the king sooner than he might expect.
Edward rages that Mortimer has escaped and Kent is now his associate. He is grieved that his son must be forced to be within their counsels, and he says they must go to Bristol to gather strength.
The Queen, Prince Edward, Kent, Mortimer, and Sir John arrive back in England. The Queen welcomes them all, and announces that “Misgoverned kings are the cause of all this wrack” (IV.4.9) and Edward has betrayed his own people and brought such sorrow upon them. Mortimer laughs that she is no warrior and should be calmer in her speeches, but says they are here indeed to right the wrongs done to the Queen and her son, and remove all baseborn flatterers from the king.
Spencer urges the king to fly, saying the Queen’s forces are too strong. Edward refuses to do so, even if they must die. Baldock cries out that they are pursued.
Kent bemoans his brother’s fate, and says his heart relents for him. He does not respect the traitor Mortimer and refuses to see him as a lawful ruler. He hopes his brother can flee, or to calm himself to deal with what is happening. Mortimer and the Queen are openly close now, even though the Queen dissembles.
The Queen, Mortimer, the Prince, and Sir John join Kent. The Queen crows that they are successful in battle and that it is time to create the Prince the Lord Warden of the realm. Kent asks what will be done with Edward, and Mortimer sneers that he need not care; Edward will be taken care of. Mortimer then whispers to the Queen that he does not like Kent’s “relenting mood” (IV.6.38).
Rice ap Howell, the Mayor of Bristol, and Spencer Senior, who is in chains, enter. Rice presents Spencer Senior as a traitor, as he is the father to the reckless Spencer who serves at Edward’s side. He also explains that Spencer and Baldock have left for Ireland with the king. The Prince asks when he can see his father and Kent mutters privately about this turn of affairs. The Queen sighs as well, but Mortimer reminds her that Edward brought it upon himself.
Mortimer then orders Spencer Senior to be taken away, and thanks Rice ap Howell. He says they must now follow Baldock and Spencer to the end.
The Abbot tells Edward, who is with Baldock and Spencer and dressed in religious garb, that they will be safe here. Edward is mournful in his distress, wishing he could just lead a quiet life. He hopes they will be undetected here, but Spencer wonders about a man with a strange expression he saw earlier.
Edward rests his head on the Abbot’s lap, querulously telling the others he wants to hear nothing of Mortimer and he is simply too weary and dismal in heart.
Suddenly, soldiers, Rice ap Howell, a Mower, and the Earl of Leicester burst in. Though inwardly hesitant, Leicester announces that Spencer and Baldock are under arrest for high treason. Edward tells him they also ought to rip his “panting breast” (IV.7.66) and take away his heart as well.
The Abbot aches to see this sight. Spencer and Edward and Baldock bid farewell, hearts heavy. Edward says they may meet again in heaven, but not on earth. Leicester tells Edward he must come to Killingworth. Edward wonders aloud that he “must” do anything. When Leicester tells him he has a litter for him, Edward asks for a hearse instead.
Edward departs, and Spencer and Baldock cry that they have lost their sunshine and they have only lived so they can now die.
By Act IV, Isabella has made it very clear that she is no longer supporting her husband and is instead allied (and sleeping) with Mortimer to bring Edward down. Even in the early acts, Isabella’s behavior was somewhat suspect. She knew how to use people, her love for her husband was quickly put aside when she could be of aid to the nobles scheming to take Gaveston down, and, as critic Sarah Munson Deats notes, her comparison of herself to complex and often malevolent Greek figures such as Circe associated her with the rebels, not her husband. Kent characterizes her well, saying “Mortimer / And Isabel do kiss while they conspire; / And yet she bears a face of love, forsooth” (IV.6.12-14).
Isabella may have loved her husband, but his sexual obsession with Gaveston and his concomitant poor treatment of her clearly led her to embrace what Mortimer had to offer. Wendy Stocker suggests that she is “no less Machiavellian than the men and even the motive is different only in part: selfishness plays a large role in all.” She evinces a great deal of hypocrisy as well, scoffing that “Misgoverned kings are cause of all this wrack” (IV.3.9), and that Edward’s “looseness hath betrayed thy land to spoil / And made the channels overflow with blood” (IV.3.11-12), all the while ignoring her own adulterous, rebellious behavior. She is also problematic in her invoking of God after winning the battle against Edward—“Since then successfully we have prevailed, / Thanks be heaven’s great architect and you” (IV.6.21-22)—because she ignores how Edward’s rule would have been, according to the prevailing theory of divine kingship, sanctioned by God.
Isabella’s relationship with Mortimer is considered just as problematic as Edward’s and Gaveston. Critic Christopher Shirley notes that the play “insistently links their relationship to ‘unnatural’ civil rebellion: this relationship’s erotic dimension appears more clearly as Mortimer and Isabella usurp power.” The complexity of Mortimer’s rebellion is that while he is an espouser of hierarchy, order, and tradition, he is also willing to topple the figure at the top of hierarchy—again, divine kingship would be the prevailing idea of the day—and elevate himself to the position. William B. Kelly sees Mortimer’s view of hierarchy as something that is “a social construct to be manipulated to his own ends” and that he “attempts to maintain the hierarchy’s form without the fixity of his own subject position within it.” Mortimer is not stupid and he is not irrational; he is simply too prideful and risks too much. Jon Surgal states that “It is Fortune herself who brings Mortimer down, and his own ambition is her accomplice.”
All of the characters have their own interpretation of what makes someone fit to rule, and it usually supports their own personal goals of attaining wealth or power. The only one who seems to have an impartial, pragmatic view on the situation is Kent, but it is also easy to label him as a vacillator given that fact that he first supported Edward, then the nobles, and then Edward again. Nevertheless, he does ultimately decide that while Edward was foolish, Mortimer is the real traitor: “Mortimer, why dost thou chase / Thy lawful king, thy sovereign, with thy sword?” (IV.6.3-5). Kent decides that the best thing for him to do is look over and protect Prince Edward, and then free Edward II. These choices get him killed, but he remains one of the more likable characters in a play remarkably free of such figures.