| 1 | Martin | Stukely | Gerard's friend. Deceased. |
| | Bon-Bon | Stukely | Martin's rich wife. |
| | Priam | Jones | A horse trainer. |
| | Tallahassee | | The steeplechaser. |
| | Lloyd | Baxter | Tallahassee's owner. |
| | Gerard | Logan | Martin's friend. Narrator. |
| | Eddie | Payne | Martin's racehorse valet. AKA: Ed. |
| | Uncle | Ron | Gerard's uncle. |
| | Pamela Jane | Evans | Gerard's assistant. |
| 2 | Catherine | Dodd | The detective constable. |
| | Marigold | Knight | Bon-Bon's mother. |
| | Worthington | | Bon-Bon's chauffeur. |
| | Daniel | Stukely | Martin and Bon Bon's eldest son. |
| | Arthur | Robins | A bookmaker. Rose's grandfather. |
| | Rose | Robins | Eddie's daughter. Victor's aunt. |
| | Norman | Osprey | A bookmaker. Rose's companion. |
| | John | Irish | Gerard's worker. |
| | John | Hickory | Gerard's worker. |
| 3 | Victor | Verity | Ed Payne's grandson. |
| | Tom | Pigeon | The man who rescued Gerard. Aka: The Backlash. |
| 4 | Doctor | Force | Martin's mystery companion. Aka: White-Beard, Adam Force. |
| 6 | Gina | Verity | Vic's mother. |
| | Black-Mask | Four | The mystery man who attacked Gerard. |
| | Jim | | Gerard's driver. |
| | George | Newnes | The man who built the mansion on Hollerday Hill. |
| | A | Spokesman | The informant on Dr. Force. |
| 8 | George | Lawson-Young | A professor of respiratory medicine. |
| 9 | Kenneth | Trubshaw | The trophy chairman. |
| 10 | Paul | Crachet | Catherine's partner. |
| 11 | Leicester | Steward | The Steward of Cheltenham. |
| 12 | Shepherd | | The police superintendent. |
