Book 7 | Ch:25 - Shell Cottage

SPOILERS:

Griphook agrees to help break into Gringotts in exchange for the Sword of Godric Gryffindor, which he considers to be rightfully goblin property. Harry and Ron agree in bad faith, planning to keep the blade for destroying the remaining Horcruxes.

Lupin arrives at the cottage to announce the birth of his son and asks Harry to be the boy's godfather. Bill takes Harry aside in the confusion to warn him against trusting goblins such as Griphook.