A scientist's substituted monkey and his subsequent murder are a case for Colonel March.
| Name | Type | Role | |
|---|---|---|---|
| Leslie Slote | Writer | ||
| Richard Burrell | Guest Star | ||
| Percy Marmont | Guest Star | ||
| Ann Gudrun | Guest Star | ||
| Victor Platt | Guest Star | ||
| John Schlesinger | Guest Star | ||
| Bernard Knowles | Director |