| Pro | Edith | Foy | Donalda's housemaid. |
| | Therese | Laporte | Donalda's housekeeper. Deceased. Aka: Tess, Theresa. |
| | Father | Alphonse | A priest. |
| | Father | Corbiere | Father Alphonse's friend. |
| 1 | Alice | Black | A prostitute. The owner of the backyard where Therese's dead body was found. |
| | Bernnadette | Weston | Alice Black's friend and housemate. Aka: Ettie. |
| | James | Mccay | Alice's boss. |
| | Oliver | Wicken | A 2nd class constable. |
| 2 | William | Murdoch | Protagonist. A detective inspector. |
| | Crabtree | | Murdoch's constable. |
| | Johnson | | Murdoch's associate. |
| | Grasett | | The Chief Constable. |
| | Richmond | | A policeman. |
| | Cavendish | | A police photographer. |
| | Foster | | Cavendish's colleague. |
| | Father | Fair | The priest at St. Paul. |
| | Beatrice | Kitchen | Murdoch's landlady and close friend. |
| | John | Tinney | Murdoch's acquaintance. |
| | Wiggins | | One of the gossipers. |
| | Driscoll | | Wiggin's neighbor. Another gossiper. |
| | Elizabeth | Milner | Murdoch's lover. Deceased. |
| | Samuel | Quinn | Alice and Bernadette's housemate. |
| | Mr. | Webster | A tailor. |
| | Princess | | Mr. Quinn's dog. |
| | Prince | Albert | Mr. Quinn's dog. |
| 3 | Donalda | Rhodes | Dr. Rhode's wife. Therese's boss. |
| | Marianne | | Donalda's friend. |
| | Harriet | Shepcote | Owen's girlfriend. |
| | Owen | Rhodes | Donalda's son. |
| | Cyril | Rhodes | Donalda's husband. |
| | Joe | Seaton | The stable lad. |
| | John | Foy | Edith's wife. Donalda's butler. |
| 4 | Arthur | Kitchen | Beatrice's son. |
| | Henry | Stanley | A biographer. |
| | Thomas | Brackenreid | The inspector of Murdoch's division. |
| | Mansfield | Otranto | Murdoch's dancing professor. |
| 5 | Sergeant | Seymour | Murdoch's colleague. |
| | Graham | | A young policeman. |
| | Robert | Moffat | A pathologist. |
| | Godfrey | Shepcote | Harriet's father. An alderman. |
| | George | Canning | Godfrey's driver. |
| | Martha | Stone | The Rhodes's former housemaid. |
| | Ezekiel | Stone | Martha's father. |
| 6 | Sprague | | Owen's friend. |
| | Hugh | MCDonough | Owen's friend. The Yeoman's medical officer. |
| 7 | Davidson | | Owen's teacher. |
| 8 | Letitia | Wright | Mrs. Rhodes's friend. |
| | Mathilda | Kleiser | Mrs. Rhodes's friend. |
| 9 | Charles | Elrod | The newspaper boy. Aka: Carrot. |
| 10 | Jack | | Alice's friend. |
| 12 | Maria | Jenkins | Alice's deaf neighbor. |
| | Courtney | | Owen's classmate. |
| | Dr. | Cavin | The demonstrator. |
| | Silver | | The Rhodes's horse. |
| 13 | Jimmy | Gallagher | The man who helped Jenkins. |
| | Zephaniah | | The man who found Alice's dead body. |
| | Mrs. | Lewis | Mrs. Kitchen's acquaintance. |
| 14 | Mrs. | Phillips | The woman who saw the carriage. |
| | Palmer | | A doctor. |
| | Pritchard | | A doctor. |
| | Lamson | | A doctor. |
| 15 | Mary | Stockdale | Cyril's nurse. |
| | Walter | Latimer | One of Cyril's patients. |
| | Mrs. | Spoffard | One of Cyril's patients. |
| | Dickie | Latimer | Walter's son. |
| 17 | Fred | Vose | A shop owner. John's acquaintance. |
| | J. | Carveth | A medical bookseller. |
| | Dr. | Osler | A doctor. |
| | Mr. | Grant | The porter. |
| | Mr. | Beresford | One of the medical students. |
| | Llewelyn | | The lone student. |
| 19 | John | Keene | The steward at the Yeoman club. Aka: Sean Kelly. |
| | Lothar | Reinhardt | The founder of the Yeoman club. |
| | Minnie | | Kelly's wife. |
| | Forsyth | | Kelly's assistant. |
| | Humphrey | | The Yeoman club's waiter. |
| 21 | Mr. | Webster | Ettie's boss. |
| | Tsar | | One of Mr. Quinn's dogs. |
| Epi | Doris | Winn | The Rhodes's new cook. |
| | Enid | | Beatrice's new tenant. A widow. |
