Tips: Once in the core, you can't quit. So choose droids with good lasers, Jack and Spud for example. The Quadralien mother is made up of four separate pieces grouped together and surrounded by Earthling boxes. The mother can only be destroyed by blowing up each box from a different direction. From the starting point there are three exits: north, east, and west. Go east and destroy the first box, return to the starting point, and go north to destroy the second box. You will now have both droids to blow the remaining boxes. Go West through the one-way force field, and get the other. Don't forget to keep recharging.