With the Doctor suffering from the time experiment, the clandestine schemes of others start coming to light, along with the secreted purposes to which the tachyonic generator has been used.
| Name | Type | Role | |
|---|---|---|---|
| David Fisher | Writer | ||
| John Collins | Guest Star | ||
| David Haig | Guest Star | ||
| Adrienne Corri | Guest Star | ||
| Roy Montague | Guest Star | ||
| Martin Fisk | Guest Star | ||
| Andrew Lane | Guest Star | ||
| Nigel Lambert | Guest Star | ||
| Lovett Bickford | Director |