| | | | Part I |
| 1 | Hercule | Poirot | The famous detective. |
| | Anthony | Trollope | Novelist. |
| | Raymond | Boynton | Mrs. Boynton's step son. A man planning to kill his mother. |
| | Carol | Boynton | Mrs. Boynton's step daughter. |
| | Nadine | Boynton | Lennox's wife. |
| | Lennox | Boynton | Mrs. Boynton's step son. |
| 2 | Sarah | King | Someone Raymond met at the train. |
| | Theodore | Gerard | A physician studying the Boynton family behavior. Sarah's old acquaintance. |
| 3 | Mrs. | Boynton | Elmer's second wife. |
| 4 | Ginerva | Boynton | Mrs. Boynton's daughter. aka: Jinny. |
| 5 | Mr. | Cope | The Boynton family friend. aka: Jefferson Cope. |
| | Gabriel | Steinbaum | Financer. |
| | Manders | Stone | Veteran English archaeologist. |
| | Lady | Westholme | A woman who is very prominent in Politics. aka: Mrs. Vansittart. |
| | Elmer | Boynton | Raymond and Carol's father. |
| 10 | Lord | Westholme | Lady Westholme's husband. |
| | Amabel | Pierce | The fourth member of the party. |
| | | Mahmoud | Sarah's fellow traveller. aka: The Fat Dragon Man. |
| | | | Part II |
| 1 | Colonel | Cadbury | Police officer. Handles Mrs. Boynton's case. |
| | Colonel | Race | Colonel Cadbury's colleague. |
| 10 | Abdul | | Bedouin. Servant. |
| | Mohammed | | Bedouin. Servant. |
| | Aziz | | Bedouin. Servant. |
| | Aissa | | Bedouin. Servant. |
