| 1 | Lawrence | Wargrave | Judge.
Accused of killing E. Seton. aka:Justice Wargrave. |
| | | | Soldier Island - Originally owned by an American millionaire. |
| | Ulick Norman | Owen | Invited rich & classy guests to party at Soldier Island. |
| | Gabrielle | Turl | Hollywood filmstar. Bought Soldier Island. |
| | Constance | Culmington | Justice Wargrave's friend. |
| | Vera Elizabeth | Claythorne | Mr. Owen's secretary. Apparently killed Cyril Ogilvie Hamilton. |
| | Mrs. | Hamilton | Cyril's mother. |
| | Hugo | Hamilton | Vera's lover. Cyril's uncle. |
| | Philip | Lombard | Captain. Guilty to the death of 21 men in an African Tribe. |
| | Isaac | Morris | Mr. Owen's assistant. |
| | Emily Caroline | Brent | Old maid. Apparently responsible for death of Beatrice Taylor. |
| | John Gordon | Macarthur | General. Apparently killed Arthur Richmond. |
| | Spoof | Leggard | General Macarthur's friend. |
| | Johnnie | Dyer | General Macarthur's friend. |
| | Elmer | Robson | A young American billionaire. Built Soldier Island. |
| | Edward G. | Armstrong | Doctor.
Apparently killed Louisa Mary Clees. |
| | Anthony J. | Marston | Rich guy. Apparently killed John and Lucy Combes. |
| | William Henry | Blore |
Ex-detective. Apparently killed J. Landor. Aka: Mr. Davis. |
| | Thomas | Rogers | Mrs. Rogers's wife. Apparently killed Jennifer Brady. |
| | Ethel | Rogers | Mr. Rogers's husband. Apparently killed Jennifer Brady. |
| 2 | Jim | | Porter with a suitcase. |
| | | | The Seven Stars - A little inn. |
| | Fred | Narracott | Mr. Owen's boat driver. |
| 3 | Mrs. | Oliver | Emily's acquaintance. |
| | Mrs. | Odgen | Emily's acquaintance. |
| | Badger | Berkeley | Anthony's friend. |
| 4 | Edward | Seton | A suspect from Justice Wargrave's former case. |
| | Cyril Ogilvie | Hamilton | Hugo's son. A child Vera took care of. |
| | Arthur | Richmond | General Macarthur's old officer. |
| | John | Combes | The kid Anthony apparently ran over. |
| | Lucy | Combes | The kid Anthony apparently ran over. |
| | Jennifer | Brady | Mr. and Mrs. Rogers's old boss. |
| | James Stephen | Landor | Bank robber Blore caught. |
| | Louisa Mary | Clees | Dr. Armstrong's old patient. |
| 5 | | Matthews | Seton case lawyer. |
| | Leslie | Macarthur | General Macarthur's wife. |
| | Tom | Brent | Emily's uncle. |
| EP | Thomas | Legge | Assistant commissioner of Scotland Yard. |
| | Maine | | Soldier Island case inspector. |
| | Beatrice | Taylor | Emily's maid. |
