LOCATION: Wiltshire, England DATE: April 20th Greg Halliday is fed up with his work as a chemical engineer creating weapons that can obliterate the population of large cities. He leaves his job with a canister of the deadly chemical. The Department is out to find him before others who want the chemicals get to him -- or before Halliday uses the weapon himself.
| Name | Type | Role | |
|---|---|---|---|
| Harry W. Junkin | Writer | ||
| Anthony Hopkins | Guest Star | Greg Halliday | |
| Frederick Jaeger | Guest Star | Major Harwood | |
| Colin Gordon | Guest Star | Doctor Stickney | |
| Leslie Norman | Director | ||
| Brian Worth | Actor | Ruckert | |
| David Rendall | Actor | Policeman | |
| Mark Elwes | Actor | Corbett | |
| Peter Wyngarde | Actor | Jason King | |
| Nosher Powell | Actor | Carl Young | |
| Peter Graves | Actor | Reggie | |
| Joel Fabiani | Actor | Stewart Sullivan | |
| Larry Martin | Actor | Mechanic | |
| Rosemary Nicols | Actor | Annabelle Hurst | |
| Eleanor Summerfield | Actor | Mrs. Evans | |
| Charles Lamb | Actor | The Porter | |
| Dennis Alaba Peters | Actor | Curtis Seretse |