King Henry begins this scene by wondering where his son is. He reflects that he hasn’t seen the son in three months, and that the “wanton and effeminate boy” can most likely be found in one of London’s taverns. Henry does say, however, that there is promise and sparks of hope within his son.
Henry here foreshadows much of the family drama that will take place in the following plays, which depict, as Henry here predicts, Henry’s son’s struggles, faults, and ultimate rise to grace and power.
At this moment a flustered Aumerle enters and asks for a moment alone with the king. He then falls to his knees and begs for a pardon, though he does not wish to say what for. Before he’ll say what it is, he wants to lock the door to the room for privacy, and Henry consents, though York soon begins knocking and crying out that Henry should beware. Alerted to danger, Henry draws his sword and lets York into the room.
Aumerle has beaten his father to the king in hopes of receiving a royal pardon before the nature of his treasonous crime can be revealed. Even though he has just taken the throne, Henry is immediately on guard and draws his sword at a moment’s notice.
York then gives Henry the writing that revealed the plot. While Henry cries out about the conspiracy and remarks that York’s goodness was not transferred to his son, the Duchess of York arrives to beg for Aumerle’s life. She drops to her knees and begs him to pardon Aumerle, who immediately joins her in begging. Meanwhile, York kneels, too, and urges Henry not to be too merciful. The Duchess, though, says that York is not earnest in his pleas, and that really he hopes that Henry will pardon Aumerle. After much begging, Henry pardons Aumerle, but orders the capture and death of all the other conspirators.
In one of his first decisions as king, Henry combines both mercy and harsh punishment. For Aumerle (possibly due to family bonds) he offers forgiveness, but for the other conspirators, Henry gives only death. Killing the other conspirators is an act of self-preservation, as Henry needs to appear strong on the throne so as to discourage others from rebelling or attempting to assassinate or depose him.