Two murderers smother Gloucester in his bed. Suffolk enters and asks if they are done. He sends them to his house to be paid. Henry, Margaret, Beaufort, and Somerset enter the adjoining room. Henry tells Suffolk to summon Gloucester for his trial. Henry orders the lords to prepare for a fair trial, which Margaret supports. Suffolk returns from the next room to announce that Gloucester is dead. Henry faints. Suffolk tries to help him up, but the king curses him, accusing Suffolk of murderous tyranny. Margaret asks Henry why he is so cruel to Suffolk, who didn't like Gloucester but now weeps at his death. She, too, sheds tears, despite her struggles with Gloucester. She pities herself, asking what people will say about her, now that Gloucester is dead--will they suspect she had a role in his death? She bewails her position as queen yet suspected of infamy. But Henry weeps for Gloucester.
Margaret accuses Henry of ignoring her in his grief for Gloucester. Why did she come to England in such a difficult crossing, she asks, for such bad treatment? The king's flinty heart is harder than the cliffs against which she might have been thrown. She was bewitched, she declares, by Suffolk's French tales about Henry's greatness, for Henry was not so wonderful as Suffolk pretended. She wishes she might die, since Henry doesn't care about her.
Warwick and Salisbury enter, with a crowd of commoners. They have heard reports that Gloucester was murdered by Beaufort and Suffolk, and the commoners want to find what happened. Henry says Gloucester is dead, but no one knows how. Warwick and Salisbury go to look at the body. Henry says he suspects some violent hand has caused the death of Gloucester. Warwick brings out the body and reports that he, too, thinks Gloucester was killed. Warwick notes the signs of struggle and horrible expression on Gloucester's face as proof that he was murdered. Suffolk asks who could have killed him when he was in the protection of himself and Beaufort, but Warwick points out that Gloucester was the sworn enemy of both men. Margaret asks if Warwick is making accusations, but Warwick says he is merely pointing out the suspicious facts. Suffolk dares Warwick to accuse him; Beaufort falls ill and is led out with Somerset's assistance. Warwick accuses Suffolk of murder; the two argue and both depart.
Then, Suffolk and Warwick reenter with swords drawn. Suffolk tells Henry that Warwick has set his commoners against him. Salisbury enters with reports that the commoners demand Suffolk be killed or banished. They believe he killed Gloucester and fear for the king's well-being, for Suffolk is a sly serpent who intends to do harm to the king. The commons outside shout for a response. Henry sends Salisbury to thank them for their care and to tell them he will do as they ask and banish Suffolk. Margaret pleads for Suffolk, but Henry tells her not to bother. He tells Suffolk be must be gone in three days, and he departs with Warwick.
Margaret and Suffolk remain. Margaret wails about their misfortune, and Suffolk curses his enemies. Margaret kisses his palm and urges him to go so she can express her complete misery. She says she will have him called back to England or be banished herself, so she can again be with him. Suffolk says he could live in any wilderness if she were there, so to be banished both from England and from her is the worst punishment. A messenger passes through with news that Beaufort is terribly ill, talking madly as if he were addressing Gloucester's ghost and revealing his secrets aloud. Margaret repeats her woe at Suffolk's misfortune and urges he depart. He says he can't live if he leaves her and would rather remain and die. He kisses her and asks her permission to stay and brave what will happen. She sends him away to France and promises to be in touch.
Henry, along with Salisbury and Warwick, enters Beaufort's chamber. Beaufort raves about the ravaged form of Gloucester, saying he will confess. The lords observe that Beaufort's death pangs are not peaceful, betraying a troubled and guilty soul. He dies, with Warwick noting that such an unpleasant death signifies a terrible life. Henry says not to judge, for they are all sinners.