| 1 | Stranger | | Protagonist of The Stranger book. |
| | Herbert | | The Stranger's dog. |
| | Herbert (2) | | Clare's dog. |
| | Clare | Cassidy | Protagonist. A teacher and a writer. |
| | Peter | | One of Clare's creative writing students. |
| | Una | | One of Clare's creative writing students. |
| | Ted | | One of Clare's creative writing students. |
| | Roland | Montgomery-Holland | The author of The Stranger. |
| | Georgia | Cassidy-Newton | Clare's daughter. Aka: Georgie. |
| | Simon | Newton | Georgia's father. Clare's ex-husband. |
| | Rick | Lewis | Clare's department head. |
| | Ella | Elphick | Clare's close friend and co-teacher. Murdered. |
| | Tony | Sweetman | Talgarth High's school principal. |
| | Daisy | Lewis | Rick's wife. |
| | Debra | Green | Clare and Ella's friend and co-teacher. |
| 2 | Jen | | Clare's best friend. |
| | Cathy | | Clare's best friend. |
| | Megan | Williams | The former principal of Talgarth High. |
| | Alice | Avery | R.M. Holland's wife. |
| | Andy | | The owner of Doggy Day Care. |
| | Harbinder | Kaur | A female detective. One of the narrators. A former Talgarth High student. |
| 3 | Neil | Winston | Harbinder's partner. A detective investigator. |
| | Henry | Hamilton | A senior English lecturer at Cambridge. Clare's new found friend. Aka: H.H.H. |
| | Nigel | Elphick | Ella's father. |
| | Sarah | Elphick | Ella's mother. |
| | Leo | Green | Debra's husband. |
| 4 | Fleur | Newton | Simon's new wife. |
| | Sebastian | | Clare's ex-boyfriend. |
| 5 | Edmund | | Hamilton's assistant. |
| | William | Petherick | A theology teacher. Holland's friend. |
| | Marianna | | Holland's alleged daughter. |
| | Thomasina | Holland | Holland's sister. |
| | Ty | Greenall | Georgia's boyfriend. |
| | Martin | Cassidy | Clare's brother. |
| | Natasha | White | Georgia's best friend. Aka: Tash. |
| | Jonnie | | Clare's friend. |
| | Susan | | Clare's friend. |
| 6 | Vera | Prentice | Clare's co-teacher. |
| | Alan | Smith | Clare's co-teacher. |
| | Anoushka | Palmer | Clare's co-teacher. |
| | Don | | The teacher who covers Ella's class. |
| | Josh | Brown | One of the students at Talgarth High. |
| 7 | Paul | | Ella's friend. |
| 8 | Pippa | | Georgia's friend. |
| | Bastian | | The leader of Hell club in The Stranger book. |
| | Gudgeon | | The Stranger's friend. |
| | Wilberforce | | Gudgeon's colleague. |
| | Collins | | Lord Bastian's henchman. |
| 9 | Patel | | A policeman. |
| | Olivia | Grant | Patel's partner. A female police officer. |
| 10 | Malone | | A senior investigating officer. |
| | Miss | Cathcart | Harbinder's former English teacher. |
| 11 | Bradley | Jones | Ella's ex-lover. |
| 12 | Sadie | Jones | Bradley's daughter. |
| | Kush | Kaur | Harbinder's brother. |
| | Gary | Carter | Harbinder's first boyfriend. A geography teacher. |
| | Liz | Francis | The deputy head. |
| | Tom | Creeve | One of Ella's students. |
| | Patrick | O'Leary | One of Ella's students who sent her a Valentines card. Georgia's friend. |
| 13 | Dipa | | Harbinder's aunt. |
| 14 | Mr. | Patterson | The former caretaker of Talgarth High. |
| 16 | Bryony | Hughes | Georgia's teacher. |
| | Venetia | Sherbourne | One of Georgia's best friends. |
| | Rosie | | Patrick's girlfriend. |
| 17 | Little | Bear | A member at MySecretDiary.com. |
| | Cyber | Wolf | A member at MySecretDiary.com. |
| 18 | Dave | Bannerman | One of the caretakers of Talgarth High. |
| 19 | Isla | Bates | Georgia's schoolmate. |
| | Paige | | Georgia's friend. |
| | Dorothy | Ladden | Harbinder's former teacher. |
| 23 | Freddy | Hamilton | Henry's son. |
| | Luke | Hamilton | Henry's son. |
| | Derek | | A police sergeant. |
| | Jill | Monroe | A police officer. |
| 26 | Kelly | | Neil's mother. |
| | Lily | | Harbinder's nephew. |
| | Maggie | O'Hara | The FLO of Lewis's family. |
| | Lauren | | Mrs. Lewis's sister. |
| | Kiaan | | Harbinder's nephew. |
| | Alisha | | Harbinder's niece. |
| | Abid | Kaur | Harbinder's brother. |
| | Cara | Kaur | Abid's wife. |
| 27 | Miss | McKenzie | Talgarth High's librarian. |
| 28 | Bella | | The handwriting expert. |
| 29 | Collin | Harris | The Chief Investigator. |
| 30 | Declan | O'Leary | Patrick's brother. |
| | Maureen | O'Leary | Patrick's mother. |
| 32 | Lucca | | Clare's former boss. |
| 35 | Ronnie | Bellows | A student who hated Rick. |
| 39 | Steve | Hollings | The Detective Inspector on Simon's attack. |
| 41 | Eva | Smith | The Stranger's friend. |
| 42 | Alicia | Sherbourne | Venetia's mother. |
| 43 | Anna | White | Tash's mother. |
| 46 | Jim | Harris | A Detective Sergeant. |
