| 1 | Roger | Angmering | Built a big house on Leathercombe Bay. |
| | Hercule | Poirot | The famous Belgian detective. |
| | Carrie | Gardener | Odell's wife. American tourist. |
| | Odell | Gardener | Mrs. Gardener's husband. |
| | Emily | Brewster | Athletic woman with a pomeranian. |
| | Kelso | | The cook in Jolly Roger. |
| | Rosamund | Anne Darnley | Owner of London's best-known dressmaker. |
| | Cornelia | Robson | Mrs. Gardener's acquaintance. |
| | Major | Barry | Retired Indian army. |
| | Irene | Gardener | Mrs. Gardener and Odell's daughter. |
| | Stephen | Lane | Clergyman who took Mrs. Gardener's place, |
| | Christine | Redfern | School teacher. Patrick's wife. |
| | Patrick | Redfern | Christine's husband. A good swimmer. |
| | Helen | Stuart Marshall | Former stage star. Victim. aka: Arlena Stuart. |
| 2 | Kenneth | Marshall | Arlena's husband. Rosamund's friend. aka: Ken. |
| | Lord | Cordington | Infatuated with Arlena. |
| | Roger | Erskine | Left his money to Arlena. |
| | Linda | Marshall | Kenneth and Ruth's daughter. Arlena's step-daughter. |
| | Arthur | Hastings | Hercule's friend. |
| 3 | Ruth | Marshall | Kenneth's former wife. Linda's mother. |
| | Horace | Blatt | Cheerful tourist. Rich. |
| 5 | Inspector | Colgate | Police detective working on Arlena's murder case. |
| | Dr. | Neasden | Medical examiner. |
| | | Hawkes | Policeman. |
| | Colonel | Weston | Chief constable. Hercule's friend. |
| | Mrs. | Castle | Owner of Jolly Roger Hotel. |
| | George | | An attendant on Jolly Roger's Bathing Beach. |
| | William | | Beach attendant. |
| 6 | Major | Cowan | Regular visitor of Jolly Roger Hotel. |
| | Mrs. | Cowan | Major Cowan's wife. Jolly Roger's hotel guest. |
| | Pamela | Cowan | Major Cowan's daughter. Jolly Roger's hotel guest. |
| | Master Robert | Cowan | Major Cowan's son. Jolly Roger's hotel guest. |
| | Master Evan | Cowan | Major Cowan's son. Jolly Roger's hotel guest. |
| | Mr. | Masterman | A regular visitor of the Jolly Rogers Hotel. |
| | Mrs. | Masterman | Mr. Masterman's wife. |
| | Edward | Masterman | Mr. and Mrs. Masterman's son. |
| | Jennifer | Masterman | Mr. Masterman's daughter. |
| | Roy | Masterman | Mr. Masterman's son. |
| | Andrew | Baston | Jolly Rogers Hotel employee. |
| 8 | Gladys | Narracott | Chambermaid. |
| | Inspector | Japp | Chief constable. Hercule's friend. |
| 9 | Phillips | | Police sergeant. |
| | Henry | | Bartender at Jolly Rogers. |
| | Chief Insp. | Ridgeway | Chief constable in charge of dope business. |
| 11 | Nellie | Parsons | Was strangled. Deceased. |
| | Alice | Corrigan | Was killed by her own husband. |
| 12 | Edward | Corrigan | Alice's husband. |
