Because Scarlet was born an albino, and her fellow citizens immediately left her out to die in desert. An old mutant named Harold found her, and took her in. She traveled with him all over California, listening to his tales of adventure with the Vault Dweller. Finally, when she was old enough, she joined the Brotherhood of Steel, thinking that she would one day return to her birthplace and raze it to the ground. Her initial tests showed a certain... moral ambiguity that led her into the Brotherhood's special ops division. There she learned the art of sniper and stealth, and she became one of the best black ops the Brotherhood had ever seen.