Act II Scene 3
At Northumberland's castle, Northumberland appeals to his wife to make his difficult position as easy as she can, and not appear troubled by it. His wife agrees to speak no more about it and let him do whatever he wishes. But Lady Percy (Hotspur's wife and Northumberland's daughter-in-law) begs him not to go to war. She reminds him that he did not take his forces to the battle at Shrewsbury, even though he had promised to do so. That decision, she says, resulted in the death of her beloved husband. It would wrong his ghost, she continues, if Northumberland were now to think he had to uphold his honor and go and fight alongside the other rebels when he could not do so even for his own son.
But Northumberland will not be moved. He says he must fight this battle, because if he does not, there will later be another battle somewhere else in which he will be in an even worse position. But the two women come up with another plan. Lady Northumberland tells him to go to Scotland and wait and see how the rebel army fares against the King. Lady Percy agrees. She says that if the rebels gain the advantage, then he should join them, but he should wait until they have first tried their strength without him. Northumberland is persuaded, and makes plans to flee to Scotland.
This is the last we see of Northumberland, although he is mentioned again in Act 4, scene 4. He plays as inglorious a part in this play as he did in Henry IV, Part 1. In that play, his failure to send his forces to Shrewsbury probably cost the rebels' the battle, and it is the same here. Without Northumberland's army, the rebels have little chance.