| Location of first appearance | Title | Character | Gender | Age | Hair Color | Hair direction / style | Features | Relations |
| Whitehaven Mansions, Opening scene | Detective | Hercule Poirot | M | 50+ | Dark | Back | Neat moustache | |
| Whitehaven Mansions, Opening scene | Valet | George | M | 60+ | White | |||
| 1937 | ||||||||
| Whitehaven Mansion, Opening scene | Norma Restarick | F | 20+ | Dark brown | Thick Curly left | The third girl. Kind of under bite | Fancies David | |
| Borodene, Upstairs party last night | Secretary of Andrew | Claudia Reece-Holland | F | 20+ | Blond | Curly | The first girl | Fancies Andrew |
| Borodene, Upstairs party last night | Actress | Frances Cary | F | 20+ | Dark | Thick Curly | The second girl. Spot on right cheek | |
| Borodene, Upstairs party last night | Painter | David (Peacock) Baker | M | 20+ | Brown | Right | Fancies Norma | |
| Borodene, arrives | Inspector | Nelson | M | 40+ | Brown | Short curly | ||
| Borodene, Downstairs | Nanny | Lavinia Seagram | F | 50+ | Grey | Curly | "Kept to herself, few visitors, drank a lot" | Had photo of herself, Mary & Norma, 1917 |
| Referred by Inspector Nelon | Concierge | Alf Renny | M | 60+ | Grey | Moustache | ||
| Referred by Lavinia's photo | Teacher / headmaster | A J Battersby | F | 50+ | Auburn | Right | ||
| Referred by Lavinia's photo | Mary Restarick | F | Suicided when Norma was 7 | Norma's mother. Roderick's niece | ||||
| Borodene, Downstairs | Cleaning woman | F | 40+ | Dark | Curly | Cleaning up after Lavinia | ||
| Borodene, Downstairs | Lawyer | Andrew Restarick | M | 50+ | Blond, yellowy | Right | Left Mary when Norma was 5 (20 years ago) | Norma's father, Came back from travels a year ago after his brother died |
| Crosshedges | Sir | Roderick Horsfield | M | 70+ | Grey | Thinning, Right | Moustache. Blind. Knows Poirot from the war? | Norma's great uncle |
| Referred by Roderick | Secretary | Sonia Benson | F | 30+ | Brown | Wavy | Was in London while Andrew visited a few days ago | Has been Roderick's companion for 6 month |
| The Merry Shamrock | Waitress | Daphne | F | 40+ | Blond | Curly | Roundish | |
| Borodene Court, Ariadne's flat | Nurse | F | 40+ | Orangy | Curlywavy | |||
| Borodene Court, Ariadne's flat | Policeman | M | 40+ | Brown | Right | |||
| Roderick's place | Robert Orwell | M | 50+ | Sandy | Right |
| Locations | Notes |
| Whitehaven Mansions | Poirot's office and home |
| 171-175 Borodene Court, London | Flat of Ariadne, the three girls, and Nanny. The location is portrayed by Alexandra Court, London, in the TV series |
| Crosshedges, Long Basing | Lavinia's photo marked "The last happy summer, 1917, A J Batterby, Nanny Seagam, Mary, Norma" |
| Joshua Restarick Ltd | Workplace of Andrew Restarick |
| Merry Shamrock Cafe | Norma and David meets here |
| Atelier | David Baker's workplace |
| Meadowfield School | A J Battersby's school, founded 1919. In real life, there’s a Meadowfield school in SE England |
| Inheritance of Mary |
| Norma inherited the entire fortune. |
| If Norma was to die, half would go to her father, the other half to the guardian of the estate |