In Dollhouse, Eliza Dushku plays a young woman named Echo, a member of a group of people known as "Actives" or "Dolls." The Dolls have had their personalities wiped clean so they can be imprinted with any number of new personas, including memory, muscle memory, skills, and language, for different assignments. They're then hired out for particular jobs, crimes, fantasies, and occasional good deeds....explains THIS Wiki entry.