Lucas Simms is the sheriff of Megaton, he also refers to himself as the Major when the need arises. He will be the first to greet you when you enter Megaton and will tell you about the bomb in the center of the town leading to the following quest:
 The Power of the Atom
- Main Article: The Power of the Atom
You may offer Lucas Simms your services to disarm the bomb, or you might choose to take up Mr. Burke's offer and blow the town up. Upon a successful disarming of the bomb you will get a cash sum paid out in caps. The caps reward is determined by a successful or failed speech skill used on Lucas before disarming the bomb in which you ask him for a larger sum for your services. If you are successful the caps total is 500, failing however will only yield 100 caps.
During the quest there's a chance Lucas will be killed by Burke; if this happens you can still get your rewards for the quest from his son Harden Simms. There's also a Strength Bobblehead in his house.