Charlotte is taken to the deck where the captain has set up a makeshift courtroom: the crew sits in place of the jury and the captain has a cabin chair where he presides as judge.
The captain uses a Bible to swear in the whole crew.
The captain asks Charlotte how she pleads (innocent) and if she wishes to withdraw her claim to being a member of the crew (she doesn't). The trial proceeds.
The captain asks Charlotte if she wishes to accuse someone else of murdering Mr. Hollybrass. She doesn't. He then asks if any man is willing to defend Charlotte. (Nope.)
Captain Jaggery determines that the dirk belonged to Charlotte and that when he originally asked who gave it to her she lied and said it was Mr. Grummage, instead of Zachariah. So now the court establishes that Charlotte is a liar. Great.
Captain Jaggery asks if anyone saw Charlotte with the knife. After much cajoling involving the Bible, almost everyone says that they saw Charlotte with the knife.
Captain Jaggery states it is "unnatural" for a girl to carry a knife (18.92).
Charlotte objects, arguing he was the one who gave her a knife to cut away the rigging during the storm. Captain Jaggery says that's only because it was an emergency.
Captain Jaggery starts asking misleading questions about why Charlotte would have a knife, and she becomes confused.
Grimes comes forward and admits to having taught Charlotte how to use a knife. The captain gets Grimes to agree that it's unnatural for a girl to use a knife.
Captain Jaggery begins a line of argument in which he accuses Charlotte of being unnatural for being a girl working aboard a boat. He states that he and the crew have an obligation to protect "the natural order of the world" (18.159).
The captain asks Charlotte what happened to Zachariah. She testifies that he was flogged to death by the captain and Mr. Hollybrass.
The captain gets Charlotte to admit that she was angry that he flogged Zachariah, establishing motive.
Through a few rhetorical tricks, the captain argues that Charlotte is unnatural, not unusual. And so it comes as no surprise that she committed an unnatural crime: murder.
No one on the crew will defend Charlotte. Confused and frightened, she's unable to speak for herself.
The captain declares a verdict of guilty and that Charlotte is to be hanged.