As the Doctor's ethics are challenged and the two Brigadiers finally meet, Turlough plots with the Black Guardian to bring the Time Lord down once and for all...
| Name | Type | Role | |
|---|---|---|---|
| Peter Grimwade | Writer | ||
| Peter Walmsley | Guest Star | ||
| Roger Hammond | Guest Star | ||
| Brian Darnley | Guest Star | ||
| Peter Moffatt | Director |