The mole refers to an unknown individual who seemingly is working against the interest of the Dollhouse and quite possibly the Rossum Corporation as a whole. While the identity of the mole and the mole's location has never been stated, several hints have risen that the mole is someone within the Dollhouse itself. In an effort to aid in the destruction of the Dollhouse, the Mole contacted Paul Ballard through Echo and November, demonstrating an ability to use the imprinting technology,or at the very least subvert an active's imprint by way of adding hidden parameters.
In each appearance, the mole criticized Ballard's methodology in attempting to uncover the Dollhouse; it repeatedly imprinted the Actives with the phrase, "The Dollhouse deals in fantasy. That is their business, but it is not their purpose." Until late Season 2, this purpose remained unclear, but the technology developed in "A Love Supreme" and discussions held in "The Attic" hint that Rossum's overall goal is global domination. The identity of the mole remains a mystery.