you have to find barry in the lake by snowpoint city save him, then go to veilstone in front of team galatic HQ. talk to the guy standing there and he"ll give you the key
Chat with our AI personalities
it is in the team galactic headquarters in veilstone
You find it in the team galactic storage area.
Galctic Headquarters is actually the Team Galactic Veilstone Building, but you'll need a Galactic Key to enter most of the doors.
You will find the boss after you see the all the galactic people in the heardqarters the boss will be talking. after that follow you guy up and there is the boss! gl
Galactic Werehouse is in Veilstone City (west/left side) right inside coming from Solaceon Town