The season begins with the introduction of Senator Daniel Perrin, who begins investigation of the Rossum Corporation.
Terry, a nephew of one of the Rossum Company benefactor, has been left in a comatose. In an attempt to figure out if he’ll recover, Topher mapped his brain out, and finds out that Terry is a serial killer. Terry’s uncle Bradley admits that he’s trying to revive him so they can rescue his latest victim.

Episode 3 features how Sierra came into the Dollhouse, and her history reveals a shocking outcome. Senator Perrin delves deeper in his investigation of the Dollhouse, but a high ranking Rossum executive tells the L.A. Dollhouse to do nothing, prompting Echo to point out that the Senator’s wife is a Doll herself. Echo was imprinted as a hooker, wherein she creates scandal for the senator when she produces a sex tape involving them both.

Adelle and Topher travels to Washington to meet the DC Dollhouse programmer, Bennett Halverson. Echo finds that she is at large after her entanglement with the DC Dollhouse and Senator Perrin. Echo now discovers that she can access all 40 of her imprints at will. She struggles to control her memories and decided to call Ballard, the only person she can remember.

The season comes to an end when the conspiracy was finally revealed and Echo, with the help of other allies, tries to tackle Rossum Corporation to stop them from enslaving the world with their mind wipe technology.