On the battlefield, Sir Walter Blunt, wearing armor the same as that of the king, meets Douglas, who has slain the Lord of Stafford, similarly arrayed for the obvious purpose of misleading the foe. Now the Scotsman is convinced that it is Henry IV himself whom he faces, and he demands that Blunt surrender. Sir Walter does not reveal his true identity. The two fight and Blunt is slain.
Hotspur enters, speaking words of high praise to the jubilant Douglas, who believes that now "All's done, all's won" (17). Young Percy recognizes Blunt and disillusions his fellow warrior. Both leave to renew the fight elsewhere.
There is the sound of sudden attack. Then Falstaff appears alone. He finds things quite different from what they had been in London; it is not so easy to get off "shot-free" on the battlefield; he may have to pay the bill, which is a rather steep one. Looking down at the body of Sir Walter Blunt, he finds new reason to believe that seeking honor has its grave limitations. From his soliloquy, it is learned that he led his ragged "troops" into the heart of battle and that all but two or three have been slaughtered.
Now it is the prince who arrives. His mood of complete seriousness and dedication to duty is established at once, as he sternly rebukes Falstaff for idleness and asks for the use of his sword. Falstaff boasts about his alleged valor and even claims to have taken care of Hotspur. When Hal assures him that the young rebel survives to slay Falstaff, the fat knight refuses to relinquish his sword, but offers to give Hal his pistol. It is a bottle of sack, not a weapon, which he draws from the case. Hal seizes it, strongly reproves Falstaff, and throws the bottle at him.
Alone once more, Falstaff declares that he will slay Percy if that fearsome enemy survives. But he makes it clear that he is not about to go out of his way to find such "grinning honour" as that possessed by the dead Sir Walter Blunt. Clearly, Hotspur will survive to old age as far as Falstaff is concerned.
The report of Douglas' slaying of the Lord of Stafford, his actual slaying of Sir Walter Blunt, and Hotspur's report that the insurgents "stand full fairly for the day" have the important effect of at least equalizing matters relating to the two opposing forces, despite the fact that the royalists outnumber the rebels. In other words, suspense is sustained; it is still touch and go.
Nothing could be much more incongruous, more grotesque, than the appearance of the corpulent, white-bearded, unheroic Falstaff on the battlefield. His brash claims to valor, which are at one with those made in the Boar's-Head Tavern after the Gadshill affair, and his irrepressible verbal wit ("Ay, Hal; 'tis hot, 'tis hot. / There's that will sack a city.") provide a counterbalance to the heroics in this scene, which, by themselves, might well be given such emphasis as to be a bit ludicrous — excessively melodramatic in dramatic fiction.
Falstaff has, in a metaphorical sense, brought the tavern to the battlefield. The bottle of sack, in place of the pistol in the case, is emblematic. The braggart warrior, one of the facets of his complex character, finds expression here when he assures the prince that "Turk Gregory" never matched his deeds in arms. The allusion, in all probability, is to Pope Gregory VII, noted for ferocity, here given the title of "Turk" since the Turks were held to be exemplars of cruelty.
Now in the midst of battle, the prince has no occasion to indulge in the slightest witticism in his exchange with Falstaff. Sternly he rebukes Sir John: "What, is it a time to jest and daily now?" (57). Certainly the knight's sense of timing is lamentably bad.