Richard claims to know the whereabouts of the Brotherhood of Steel Paladins and tasks the Initiate to clear the radscorpions from the Carbon warehouse before he will provide the information. As the Initiate is dependent on others to go anywhere in the game he must complete this task.
After clearing the Warehouse Main Storage and the Warehouse Auxiliary Storage you must go to the Warehouse 2nd Floor, use a crane there to move a crate, return back downstairs, and then you may enter the Warehouse Basement. When you finally arrive at the basement you will encounter the giant radscorpion, opening up the quest Kill Giant Radscorpion.
You have to kill all the radscorpions in the warehouse, including the giant abomination that sits around in the basement smashing rats. This creature might look daunting but can be easily killed with a mixture of melee attacks, dodging, and gun play. First attack it's claws, which it uses like shields, with a melee weapon until they are destroyed. Now it's open season, timing your dodges and gunfire just right, you can avoid the giant radscorpion's stinger and wear it down to nothing.
Once this radscorpion is defeated the warehouse will be clear and a prompt will appear telling you to return to Carbon.