Go to where blaine's gym used to be and you will find gary oak there(in HG/SS he is called blue) talk to him and he will go back to his gym in kanto then fight him and win then go back to the place where you get to victory road and the guard who blocked mt. Silver will let you go there, get to the top and... Oh my god! It's ash! (in HG/SS he is called red) talk to him and he will fight you, he has the best team the hardest to defeat is his pikachu that is at lv.87 defeat him and you will gain a lot of money and exp. Then he will fly away and you have finished the game but now a lot of new doors have been opened and you can now catch all-new pokemon the rest is a secret