The TARDIS arrives at a holiday camp company with the crew worried by a prediction of giant crabs and the Doctor becomes interested in the apparent madman Medok's stories of creatures that roam the colony at night.
| Name | Type | Role | |
|---|---|---|---|
| Ian Stuart Black | Writer | ||
| Anthony Gardner | Guest Star | ||
| Denis Goacher | Guest Star | ||
| Graham Armitage | Guest Star | ||
| Sandra Bryant | Guest Star | ||
| Jane Enshawe | Guest Star | ||
| Maureen Lane | Guest Star | ||
| John Howard Davies | Director |