Fugitive period hint
There is a part of the game where you must run as a fugitive in order to uncover the truth of the Ninetales legend. This begins when you climb to the top of the great canyon to tell Xatu about how you became a Pokemon. Before this, make sure that your character and your partner are at least level 20. Also, make sure that you have plenty of Oran Berries, Reviver Seeds, and Apples or Big Apples in storage and that your Pokemon knows Attract to defeat Moltres and Articuno easily.