The Doctor begins to investigate the mysteriously wealthy planet Zanak. Mentiads, a deranged Captain, strange omens, miraculous mines – what does it all mean? And what does it have to do with the Key to Time?
| Name | Type | Role | |
|---|---|---|---|
| Douglas Adams | Writer | ||
| Bernard Finch | Guest Star | ||
| Rosalind Lloyd | Guest Star | ||
| Primi Townsend | Guest Star | ||
| Bruce Purchase | Guest Star | ||
| David Warwick | Guest Star | ||
| Adam Kurakin | Guest Star | ||
| Ralph Michael | Guest Star | ||
| Andrew Robertson | Guest Star | ||
| Graham Williams | Director |