The Forerunners created large frying pans made from rock and horse dung in order to get to place to place in a really alien way... besides the fact that they were made from stone and dung, and maybe a few jet packs, the didn't sink when they where faced with water, because a big Bungie executive broke into Steve's office and changed them. When Halo 2 was released, Steve later found out that Fred had made the Gondolas better than they should of been, thus leading to the completion of the level, and soon releasing Halo 3. After Halo 3 was sold, Fred and Steve reached for their Battle Rifles and Plasma Grenades, thus leading to a nuclear explosion that destroyed Bungie H.Q. That's why there isn't going to be a Halo 4.