Eliza Dushku as Echo / Caroline Farrell
Dichen Lachman as Sierra
Enver Gjokaj as Victor
Fran Kranz as Topher Brink
Olivia Williams as Adelle DeWitt
Tahmoh Penikett as Paul Ballard
Harry Lennix as Boyd Langton
Amy Acker as Dr. Claire Saunders
Miracle Laurie as Mellie
Alan Tudyk as Alpha
Summer Glau as Bennett Halverson
Alexis Denisof as Senator Daniel Perrin
Reed Diamond as Laurence Dominic
Keith Carradine as Matthew Harding
Felicia Day as Mag