The Doctor and Dodo return to London in the present day where the Doctor becomes concerned about WOTAN, a new super-computer installed in the Post Officer Tower.
| Name | Type | Role | |
|---|---|---|---|
| Ian Stuart Black | Writer | ||
| John Doye | Guest Star | ||
| William Mervyn | Guest Star | ||
| John Cater | Guest Star | ||
| Ewan Proctor | Guest Star | ||
| Sandra Bryant | Guest Star | ||
| Alan Curtis | Guest Star | ||
| Michael Ferguson | Director |