| Sofonisba | Anguissola | The painter of "The Queen of Sheba" portrait. |
| Carter | Briggs | One of Vance's men. |
| Thierry | Carapaz | The man-in-charge of Provenance. |
| Mad | Dog | Billie's combat trainer. |
| Martin | Fairbrother | Gunther Paar's second acquisition. |
| Heather | Fanning | Executive guest service coordinator. |
| Brad | Fogerty | A junior field operative from the Museum. |
| Vance | Gilchrist | Billie's leader. The pilot. |
| Constance | Halliday | The leader of Project Sphinx. Billie's mentor. |
| Richard | Halliday | The man who hires Billie Constance Brother. AKA: Major Halliday. |
| Thomas | Hardy | A novelist. |
| Wendy | Jeong | One of Vance's associates. |
| Lilja | Koskela | The auctioneer. |
| Guido | Lomellino | Anguissola's step-son. |
| Claude | Lorrain | A Baroque artist. |
| Charles Ellison | McSween | Vance's co-pilot. AKA: Sweeney. |
| Naomi | Ndiaye | Carapaz's agent. |
| Eva | Nowak | One of Vance's associates. |
| Elisabeth | Of Valois | Queen of Spain. |
| Gunther | Paar | The man-in-charge of Acquisitions. |
| Mona | Rae | A director. |
| Helen | Randolph | Billie's colleague. |
| Natalie | Schuyler | Billie's colleague. |
| Timothy | Sullivan | The bishop. One of Billie's targets. |
| Beth | Taverner | Taverner's wife. |
| Christopher | Taverner | Billie's co-assassin and ex-lover. |
| Mary Alice | Tuttle | Billie's colleague. AKA: Margaret Ann. |
| Elizabeth | Von Waldenheim | One of Billie's targets. |
| Billie | Webster | Protagonist. An Assassin. AKA: Bridget. |
| Akiko | | Mary Alice's wife. |
| Annike | | The spa therapist. |
| Anthea | | Vance's dog. |
| Astraea | | A goddess. Daughter of Dusk and Dawn. |
| Cassandra | | Helen's assistant. |
| Elsa | | The spa receptionist. |
| Hector | | Natalie's young porter. |
| Henderson | | The real pilot. |
| Ji-Woo | | The spa front desk. |
| Kate | | Taverner's granddaughter. |
| Kenneth | | A CIA. Helen's husband. |
| Kevin | | Akiko and Mary Alice's cat. |
| Minka | | Billie's close friend. |
| Nielssen | | Sweeney's co-assassin. |
| Sarah | | Taverner's granddaughter. |
| Sophia | | The receptionist. |
| Volkmar | | The caretaker's wife. |
| X | | The principal. One of the passengers. |
