The Bomb Shelter
Gecko is Ghoul Central of the Wastes.
Fallout vets will recognize Harold who is now leader of this place. He hasn't aged much, except for that weird twig on his head. You can check his desk to get acquisition papers which you need to get the 3-step Transformer from the inventory in the reactor.
Fans of Magic: The Gathering will either love or hate the newest addiction to the Wastes: Tragic the Garnering. Be warned, if you get addicted to this, you'll slowly lose money all throughout the game, just like in real life.
Inside the reactor, you'll need special keycards; if you have high thieving skills, you can pilfer them from the main guard. If not, the yellow card is on a shelf there, easy enough to find. You'll also find a blue card, but you won't need it until later. The red card is on a shelf somewhere between the yellow doors and the red doors.
Festus is the self-appointed boss of this reactor. Get on his good side, because you'll need him later.
To fix the reactor, you need the Hy-Mag, which is in Vault City. Go check my Vault City section.
You can either use the robot to fix the reactor, do it yourself, or the easiest way: ask Festus to do it. Using the robot requires some time-consuming trial and error hacking with the computer(hint: Pluto, Neptune, Uranus, Saturn, Jupiter). Doing it yourself can get you killed and/or radiated.
After fixing it, you need to optimize it so it runs smoothly( talk to the rat king up north and underground for optimizing ideas), talk to Festus about it, and he'll give you a disk that you should insert in Vault City's main computer which is in the 3rd floor of the main Vault.
North of Gecko, there lives Skeeter who will give you the battery for you car if you can give him a Super Tool kit which you can get from Val in Vault City.