What To Do After You Defeat The Boss Of Galactic In Pkmn Platinum Where Do I Find The Galactic Boss In MT. CORNET... (Pokemon Platinum) ?

Where do i find the galactic boss in MT. CORNET... (Pokemon Platinum) ? - what to do after you defeat the boss of galactic in pkmn platinum

I beat the boss galactic galactic headquarters team and also told me that I was MT. CORNET But I find no evidence of something there ... Also can not find, Voyeur ... Some Body PLEASE HELP !!!!!!!!!