Barbara is put to work in the Dalek mine where it is revealed that the Daleks intend to use a bomb to extract the Earth's magnetic core.
| Name | Type | Role | |
|---|---|---|---|
| Terry Nation | Writer | ||
| Meriel Hobson | Guest Star | ||
| Jean Conroy | Guest Star | ||
| Graham Rigby | Guest Star | ||
| Nicholas Smith | Guest Star | ||
| Richard Martin | Director |