The Doctor discovers that the Cybermen are planning to immobilise Earth's population by transmitting a hypnotic signal broadcast through International Electromatics products.
| Name | Type | Role | |
|---|---|---|---|
| Derrick Sherwin | Writer | ||
| Peter Thompson | Guest Star | ||
| Dominic Allan | Guest Star | ||
| Edward Dentith | Guest Star | ||
| Douglas Camfield | Director |