Britannia Main cast, played by Callie Cooke Episode 3x03: Episode 3 (Aug 24, 2021) Episode 3x04: Episode 4 (Aug 24, 2021) Guest cast, played by Callie Cooke Episode 1x01: Episode 1 (Jan 18, 2018) Episode 1x07: Episode 7 (Jan 18, 2018)