With the commerce of the world grinding to a halt, the Doctor, Jamie and Zoe agree to investigate. They set off for the T-Mat Relay Station on the Moon in Professor Eldred's old-fashioned rocket.
| Name | Type | Role | |
|---|---|---|---|
| Brian Hayles | Writer | ||
| Philip Ray | Guest Star | ||
| Martin Cort | Guest Star | ||
| Terry Scully | Guest Star | ||
| Ronald Leigh-Hunt | Guest Star | ||
| Louise Pajo | Guest Star | ||
| Ric Felgate | Guest Star | ||
| Steve Peters | Guest Star | ||
| John Witty | Guest Star | ||
| Alan Bennion | Guest Star | ||
| Tony Harwood | Guest Star | ||
| Christopher Coll | Guest Star | ||
| Michael Ferguson | Director |