Harry goes to Griphook for a chat, with Hermione and Ron listening in.
Griphook wants to know how Harry got the Sword of Gryffindor.
Hmm, Harry's been kind of wondering the same thing, since the sword appeared to him in a lake, no?
And Harry has his own questions about the sword: Why did Bellatrix think the sword was in her vault?
Griphook explains that Snape swapped out the real sword for a fake one. Super puzzling. If Snape had the real sword, and the real sword made its way to Harry…hmmm…
Anyway, as it turns out, Harry wants to get into Bellatrix's vault, and he wants Griphook's help.
Griphook says the price of his help is the Sword of Gryffindor.