The Sword of Gryffindor

[Brenwen]

No: HPFGUIDX 182541

I am coming out of my lurking position where I have been for several
years, just to ask a question that may have been addressed earlier,
and I apologize if it's a repeat.

In DH - how did the sword of Gryffindor get from the hands of the
goblin Griphook [after the debacle at Gringotts Bank] back to the
sorting hat where Neville could grab it and decapitate Nagini?  (I am
not sure if I am incorrectly spelling any of these names as my book is
not handy).

This has been bothering me ever since my third or fourth reading
(listening).

Brenwen