Torchwood is defenceless and Gwen Cooper stands alone as the final sanction begins. As violence erupts and the world descends into anarchy, an ordinary council estate becomes a battleground where the future of the human race will be decided.
| Name | Type | Role | |
|---|---|---|---|
| Russell T Davies | Writer | ||
| Katy Wix | Guest Star | Rhiannon Davies | |
| Peter Capaldi | Guest Star | John Frobisher | |
| Bear McCausland | Guest Star | Steven Carter | |
| Cush Jumbo | Guest Star | Lois Habiba | |
| Louise Minchin | Guest Star | Newsreader | |
| Rhodri Lewis | Guest Star | Johnny Davies | |
| Nicholas Farrell | Guest Star | Brian Green | |
| Julia Joyce | Guest Star | Holly Frobisher | |
| Liz May Brice | Guest Star | Johnson | |
| Simon Poland | Guest Star | 456 | |
| Hilary Maclean | Guest Star | Anna Frobisher | |
| Susan Brown | Guest Star | Bridget Spears | |
| Madeleine Rakic-Platt | Guest Star | Lilly Frobisher | |
| Colin McFarlane | Guest Star | General Pierce | |
| Luke Perry | Guest Star | David Davies | |
| Lucy Cohu | Guest Star | Alice Carter | |
| Lorna Bennett | Guest Star | Female Teacher | |
| Deborah Findlay | Guest Star | Denise Riley | |
| Aimee Davies | Guest Star | Mica Davies | |
| Ian Gelder | Guest Star | Mr Dekker | |
| Rhiannon Oliver | Guest Star | Mum | |
| Euros Lyn | Director |