Zoe and the Doctor submit themselves to the Krotons' IQ tests and are selected to enter the Dynatrope, the Krotons' ship. There they watch as the crystalline Krotons are brought back to life.
| Name | Type | Role | |
|---|---|---|---|
| Robert Holmes | Writer | ||
| Patrick Tull | Guest Star | ||
| Miles Northover | Guest Star | ||
| Gilbert Wynne | Guest Star | ||
| Madeleine Mills | Guest Star | ||
| James Copeland | Guest Star | ||
| Robert LaBassiere | Guest Star | ||
| David Maloney | Director |