I think that in the info in the Item Database for the Magic Whistle from the Holy Grail, it should say something about how to get it back. I spent a while today trying to find it, and retracing my steps through the quest before finally referring to Zybez before I found out how simple it was to get it back.

 

 

 

You need to use the Fairy Ring (BJR) to get to the Fisher Realm to get the whistle back. I think it would help a lot of people if that was included somewhere in either the quest guide, or the database entry, or both. :D Thanks for reading. :)

thanks for nudging us about this, it has been noted in the quest guide and added to the items database, where you were also credited.