York and his army enter a field near St. Albans. He speaks of his journey from Ireland to London to claim the crown from weak Henry. Then, Buckingham enters, and York swiftly realizes he is a messenger from the king, so he must lie to him. Buckingham says he has been sent by the king to find out why York marches on London. York mutters to himself that he can barely restrain his fury, for he is far better than the king, more kingly in thought and action, but he must restrain himself until Henry is weaker and he is stronger. So York announces to Buckingham that he has brought the army in order to remove Somerset from his office, and he declares Somerset to be a traitor. Buckingham says Somerset is in the Tower, a prisoner. Hearing this, York dismisses his troops, telling them to report the following day for their pay.
Henry enters, asking York about his army, and York repeats his intentions regarding Somerset, and he adds that the troops could help rout Jack Cade. Then Alexander Iden enters with Cade's head. Henry is pleased and knights Iden. Then, Margaret enters with Somerset. Seeing Somerset free, York can contain himself no longer. He turns to Henry, demanding to know why he has broken faith with him. He says Henry is not a genuine king, not fit to rule or govern. He says Henry is not made to hold the scepter or wear the crown, but his own head and hand are made for such signs of office. He declares Henry will no longer rule over one who should be the ruler.
Somerset orders York's arrest for treason. York asks that his sons be called in to speak for him. York's sons Edward and Richard are called in, along with Clifford. Clifford judges York to be a madman and a traitor. Margaret says York has been arrested but will not go to the Tower, calling for his sons to speak for him. York insists he is the king and calls for Salisbury and Warwick to enter and defend him. Richard speaks of Warwick's bravery, Clifford insults Richard, and York declares they will soon teach Clifford a lesson.
Henry asks Salisbury and Warwick why they won't bow to him. He asks where their faith and loyalty have gone. Salisbury says that he believes York to be the rightful heir to the throne. Henry asks him if he did not swear allegiance to him already; Salisbury says he did, but it was a sinful oath to support a usurper, which is better to break than keep. Henry tells Buckingham to arm himself, and York tells him to gather his allies, for there will be fighting in the future. Clifford and Warwick insult each other, and Clifford's son and Richard spar verbally.
Though he counsels himself to wait until Henry is weaker, York can hold his tongue no longer, and he tells Henry of his claim to the throne, accusing him of being unfit to rule. He brings out his sons, both of whom will be future kings, Edward becoming Edward IV and Richard later wreaking havoc on the kingdom as Richard III. And now the finally struggle between Lancaster and York is out in the open.