| Pro | Maisie | Dobbs | Private inquiry agent & psychologist.
A nurse during WWI, graduate of Girton College in Cambridge, the protagonist |
| | Dr. Maurice | Blanche | Maisie's mentor, former employer, deceased |
| | Frankie | Dobbs | Maisie's father, head groomsman for Lady Rowan Compton |
| | Lady Rowan | Compton | Duchess, mother of James |
| | Mrs. Brenda | Bromley | Maisie's cook |
| | Charles | Wickham | One of the policemen following Maisie |
| | DCS Robert | MacFarlane | Superintendent of Special Branch at Scotland Yard |
| 1 | Billy | Beale | Maisie's assistant |
| | Doreen | Beale | Billy's wife |
| | James | Compton | Maisie's love interest, son of Lord Julian & Lady Rowan, heir to Dukedom, former employer, head of family's Corporation |
| | Sandra | Tapley | Former employee at Ebury Place mansion, the Compton's London home, friend of Maisie |
| | Eric | Tapley | Sandra's husband |
| | DC | Summers | Detective Constable at Scotland Yard |
| | Calum | Guthrie | MacFarlane's mentor, deceased |
| | Brian | Huntley | Secret Service agent |
| | Priscilla Evernden | Partridge | Maisie's long-time friend |
| | Peter | Evernden | Priscilla's brother, former intelligence agent |
| | Greville | Liddicote | Senior Fellow at Cambridge, author of children's books, pacifist during WWI, founded St. Francis College, Cambridge in 1920 |
| 2 | Reg | Martin | Eric Tapley's boss at the garage |
| | Douglas | Partridge | Priscilla's husband, a writer |
| 3 | Mrs. | Crawford | Cook at Chelstone when Maisie was a student at Girton |
| | Rosemary | Linden | Liddicote's secretary at St. Francis College |
| | Dr. Matthias | Roth | Professor at St. Francis, Liddicote's deputy |
| | Dr. Francesca | Thomas | Professor of French literature at St. Francis |
| | Delphine | Lang | Teaching assistant at St. Francis |
| 4 | Geoffrey | Tinsley | Bookseller |
| | Dr. Alan | Burnham | Professor of classics at St. Francis |
| 5 | Dunstan | Headley | Benefactor of St. Francis College |
| | Hubert | Stone | Lawyer with Stone, Tupper & Pearce in Cambridge |
| | DCI Richard | Stratton | Police investigator |
| | Tom | Sarron | Police pathologist |
| 6 | Lizzie | Beale | Billy's deceased daughter |
| | Mrs. | Beale | Billy's mother |
| 8 | Cyril | Linden | Resident of Ipswich, possible relative of Rosemary Linden |
| | Rose Thurlow | Linden | Cyril's sister-in-law, deceased |
| | Mary | Linden | Cyril's wife |
| 9 | Miss | Hawthorne | Bookkeeper for St. Francis College |
| | William | Walling | Businessman whose office Sandra broke into |
| | Jennifer | Penhaligon | Professor at Somerville College, Cambridge, who provided an academic reference for Francesca Thomas |
| | Robson | Headley | Dunstan's son, student at St. Francis, seeing Delphine Lang, on the debate team |
| 10 | Martin | Headley | Dunstan's eldest son, killed in WWI |
| 11 | Hans Wilhelm | Thost | Journalist, leader of the London group of the Ortsgruppe |
| | Mrs. | Hawkins | Priscilla's cook |
| 12 | Michael | Klein | Maisie's solicitor |
| 13 | Clarence | Chen | Half-Chinese mob boss in Limehouse, expert in martial arts |
| 14 | Dr. Trevor | Petit | Lecturer in politics & history at King's College |
| | Arthur | Henderson | Retired professor, former colleague of Liddicote |
| | Mrs. | Mills | Henderson's housekeeper |
| | David | Thurlow | Rose Linden's nephew, conscientious objector during WWI, died in prison |
| | Adam | Thurlow | Son of David, one of Alice's brothers |
| | Alice | Thurlow | Rosemary Linden's real identity, daughter of David |
| | Amber | Thurlow | Daughter of David, Alice's sister |
| | Alfie | Thurlow | Son of David, Alice's other brother, a student |
| 15 | Ursula | Thurlow | Alice's mother, David's widow, wheelchair-bound with a nerve disease (probably MS) |
| | DI | Caldwell | Detective Inspector at Scotland Yard |
| | Mr. | Carter | Head servant at Chelstone Manor |
| 17 | Dieter | | Husband of Francesca Thomas, captured & died in WWI |
| 18 | Mr. | Judge | Construction foreman at the Ebury Place refurbishment project |
| | Tarquin | Partridge | Priscilla's youngest son |
| | Elinor | | The Partridge sons' governess |
| 19 | Daniel | | One of Maisie's philosophy students at St. Francis |
| | Rebecca | Inglesson | Another St. Francis student |
| | Fred | | Another St. Francis student |
| Epi | Margaret Rose | Beale | Billy & Doreen's new baby |