Alistair Gordon Lethbridge-Stewart, now a UN Brigadier, confirms to the Doctor that there is something suspicious occurring at International Electromatics. Zoe and Isobel's investigation places them in terrible danger, and Jamie tries to save them.
| Name | Type | Role | |
|---|---|---|---|
| Derrick Sherwin | Writer | ||
| Geoffrey Cheshire | Guest Star | ||
| Douglas Camfield | Director |