Billy isn't the least bit suspicious as he makes his way to Vere's cabin. He thinks that perhaps Vere will promote him and just wants to ask what Claggart has to say about him.
When he enters, Vere has him shut the door and demands that Claggart make the accusation to Billy's face.
Claggart approaches him as if he is a physician approaching a patient, and accuses him of conspiring to mutiny.
Billy is shocked. He can hardly take it in. Claggart's eyes seem to turn dark, "gelidly protruding like the alien eyes of certain uncatalogued creatures of the deep" (19.4).
Vere demands that Billy speak and defend himself, but the horror of the situation has caused Billy's stutter to kick in with all its force, "intensifying it into a convulsed tongue-tie" (19.5).
Though Vere didn't know about Billy's impediment, he guesses it from the tortured expression on his face. He speaks soothingly to Billy and tells him to take his time.
The unexpected kindness only makes the stutter more severe "bringing to his face an expression which was a crucifixion to behold" (19.6).
Then Billy's hand shoots out and he punched Claggart right in the forehead. Claggart slumps to the ground, and Vere looks at Billy and says, "Fated boy, what have you done! But here, help me" (19.7).
Billy and Vere lift Claggart to a sitting position.
Vere tells Billy to go wait in the stateroom until he is called. Vere has Albert summon the surgeon, who enters making his typical greetings.
Vere dismisses them and indicates Claggart, who now has black blood oozing from his nostrils and ear.
The surgeon can immediately tell that he is dead, but does the customary tests anyway.
Vere seems discomposed and laments that Claggart was "Struck dead by an angel of God! Yet the angel must hang" (19.13).
He has the surgeon help him move the body out of sight, and tells him that he will mount a drumhead court. He has the surgeon go summon the lieutenants and the captain of the marines, but he tells him to make absolutely certain to be quiet about it.